Market-Disrupting Acts in Turkey: Capital Markets Law Article 104, Communiqué VI-104.1, SPK Fines and Trading Bans

Not every abusive trading pattern is a crime. Turkish law has a second, administrative tier for market abuse: acts and transactions that cannot be explained by a reasonable economic or financial reason and that disrupt the confident, transparent and stable functioning of exchanges and other organised markets are “market-disrupting acts” where they do not constitute a crime (Capital Markets Law Art. 104(1)). The Capital Markets Board (SPK) has defined these acts in the Communiqué on Market-Disrupting Acts No. VI-104.1: tipping and trading on inside or continuous information, trading in the blackout period before financial statements are published, significant order and transaction patterns such as self-trades, matched trades, marking the close and rapidly reversing orders, trading around false or misleading information, front-running, using another person’s account without a notarised power of attorney, and trading while banned. SPK imposes administrative fines within a statutory range, which may not be less than twice any benefit obtained, after taking the person’s defence (Arts. 104 and 105). Since 2024, SPK’s trading bans and other measures under Art. 101 also apply where market-disrupting acts are reasonably suspected. This guide explains the rules, the procedure, the challenge routes and what these findings mean for foreign institutional investors. It reflects the legislation in force as at 25 October 2026.

Why market-disrupting acts matter in the 2026 cases

Market manipulation and insider dealing are crimes under Arts. 107 and 106 of the Capital Markets Law No. 6362. A criminal case needs a written application by SPK to the public prosecutor (Art. 115(1)), proof of the elements of the offence and, for several of the offences, proof of a purpose or a benefit. Much conduct that harms a market does not reach that threshold, or cannot be proven to that standard. Article 104 fills the gap. It allows SPK itself to sanction conduct that disrupts the market without having to show that a crime was committed.

For a foreign institutional investor, Article 104 matters in three ways. First, SPK decisions under Article 104 are regulatory findings about specific conduct in specific shares over specific periods; they help identify who traded, how and when, which is the starting point of any loss analysis or claim. Second, the measures SPK may take under Article 101 (trading bans, changed settlement methods, collateral requirements, transfers to other markets and trading limits) now also apply where market-disrupting acts are reasonably suspected, so they can affect shares the investor holds. Third, the definitions in the Communiqué are broad enough to reach ordinary market participants, including institutions whose order patterns, communications or information flows fall within them. The same rules that help an investor understand what happened in a share are rules the investor must itself observe.

This guide is part of a series on the legal consequences of the 2026 fund and market manipulation cases for foreign institutional investors. The criminal offences are covered in the guides to market manipulation under Article 107 and insider dealing under Article 106. This guide concentrates on the administrative regime: what the Communiqué defines as market-disrupting, how SPK proceeds and how its decisions can be challenged or used.

Article 104: the statutory test

Article 104(1) has three sentences. The first defines the concept: acts and transactions that cannot be explained by a reasonable economic or financial reason and that are of a nature to disrupt the confident, transparent and stable functioning of exchanges and other organised markets are deemed market-disrupting acts, provided they do not constitute a crime. The second gives SPK the sanction: persons who commit the market-disrupting acts determined by SPK are given an administrative fine by SPK within a range stated in the Law (TL 20,000 to TL 500,000 in the statutory text). The third sets a floor: where a benefit has been obtained in this way, the fine may not be less than twice that benefit.

Four elements follow from this wording:

1. 1. An act or transaction. Article 104 covers both conduct (for example, giving information or making a comment) and transactions (orders, trades, account movements).
2. 2. No reasonable economic or financial explanation. The test is objective. The question is whether the act can be explained by a reasonable economic or financial reason, not whether the person had a bad motive. A documented investment, hedging, liquidity or risk-management reason is therefore the core of most defences.
3. 3. Capable of disrupting the market. The act must be of a nature to disrupt the confident, transparent and stable functioning of exchanges and other organised markets. The wording refers to the nature of the act, so actual disruption does not appear to be required, but the act must have that capacity.
4. 4. Not a crime. Where the same conduct constitutes a crime, Article 104 does not apply. This reflects the general rule that, where an act is defined both as a misdemeanour and as a crime, only the sanction for the crime may be applied; where no sanction can be applied for the crime, the misdemeanour sanction applies (Misdemeanours Law No. 5326 Art. 15(3)).

Article 104 does not itself list the acts. It authorises SPK to determine them (“market-disrupting acts determined by the Board”). The list is in Communiqué VI-104.1. This structure matters for the defence: a fine under Article 104 must be based on an act that falls within one of the Communiqué’s definitions and also meets the statutory test.

The legal framework

Three layers of rules apply. The Capital Markets Law sets the concept, the sanction and the procedure. Communiqué VI-104.1, published in the Official Gazette of 21 January 2014 (No. 28889) and based on Article 104 (Communiqué Art. 2), defines the acts. It has been amended once, in the Official Gazette of 18 February 2017 (No. 29983), which replaced Article 6(1) and (2) on false or misleading information and Article 8 on exclusions. The Misdemeanours Law No. 5326 supplies the general rules on administrative fines: its general provisions apply to all acts punishable by an administrative fine, and its provisions on remedies apply unless another law provides otherwise (Misdemeanours Law Art. 3(1)).

The Misdemeanours Law expressly allows this kind of delegation. Which acts constitute a misdemeanour may be defined in a law, or a framework provision in a law that sets the scope and conditions may be filled in by the administration’s general regulatory acts; but the type, duration and amount of sanctions may be set only by law (Misdemeanours Law Art. 4). Article 104 provides the framework, Communiqué VI-104.1 fills it in, and the fine range is set by the Law itself.

Temporal application follows the Penal Code’s rules, so the law in force when the act was committed applies and a more favourable later rule benefits the person concerned; a misdemeanour is deemed committed when the act or omission takes place, not when the result occurs (Misdemeanours Law Art. 5). For conduct before 18 February 2017, the earlier wording of Communiqué Articles 6(1), 6(2) and 8 must therefore be checked.

Market-disrupting act or crime?

The same trading can be examined under Articles 104, 106 and 107. The classification determines who decides, which procedure applies and what sanction follows. A crime requires SPK’s written application to the prosecutor (Art. 115(1)) and is tried by specialised criminal courts of first instance (Art. 116(1)). A market-disrupting act is decided by SPK itself, with review by the administrative courts (Art. 105(4)).

In practice, the main differences are the mental element and the benefit. Article 107(1) requires that trades be made for the purpose of creating a false or misleading impression. Article 107(2) requires a purpose of affecting prices, values or investor decisions and that a benefit be obtained. The Communiqué’s parallel definitions do not use these elements. Misdemeanours may be committed intentionally or negligently unless the law provides otherwise (Misdemeanours Law Art. 9), and neither Article 104 nor the Communiqué requires intent. The comparison of the three regimes is also set out in the guide to insider dealing.

Key definitions in the Communiqué

Several definitions in Communiqué Article 3 determine the reach of the substantive rules. The most important is “persons acting together”, because many of the acts may be committed “alone or together with persons acting together”.

Persons acting together are, first, persons who transmit orders, carry out transactions, make transfers of cash, cash equivalents or capital market instruments, or carry out account movements in any of the following ways (Communiqué Art. 3(1)(a)):

1. 1. knowing about one or more persons’ orders or transactions, their order or trading plans or the capital market instruments they hold;
2. 2. on the basis of a tacit, oral or written agreement;
3. 3. acting under the direction of the same person or persons;
4. 4. directing one or more persons;
5. 5. using the accounts of others, with or without a power of attorney;
6. 6. using the same premises or virtual environment, computer, telephone, internet connection or any of the communication channels.

The definition also covers persons who unlawfully give information about accounts, orders, transactions or companies to those who do these things, and persons between whom, or between whose accounts or the accounts they manage or use, cash, cash equivalents or capital market instruments are transferred, directly or indirectly, under whatever name. The sixth limb is particularly wide: on its wording, the use of the same premises, computer, telephone or internet connection is enough to bring persons who place orders within the definition. Whether a combination of such persons’ orders then amounts to a market-disrupting act still depends on the substantive rules and on the reasonable-reason test.

Acts relating to inside or continuous information

Article 4 of the Communiqué starts from a principle: persons who hold inside or continuous information must keep it confidential until the necessary disclosures have been made to the public in accordance with the legislation (Art. 4(1)). It then defines three market-disrupting acts.

• ▸ Tipping and trading by recipients. Where persons who receive inside or continuous information, directly or indirectly, from its holders before it is properly disclosed trade in the relevant capital market instrument, both the holders’ giving of the information and the recipients’ trading are market-disrupting acts (Art. 4(2)). The rule applies only where the recipient trades; passing on information that is not then traded on is not caught by this paragraph, although the confidentiality principle in Art. 4(1) still applies.
• ▸ Blackout before financial statements. From the day after the end of the accounting period for which an issuer’s financial statements and reports and the audit reports are prepared, until their proper disclosure, trading in the relevant instruments by holders of inside or continuous information, or by their spouses, children or persons living in the same household, is a market-disrupting act (Art. 4(3)). This is an objective prohibition: it does not depend on the person actually using any information about the results.
• ▸ Trading between finalisation and disclosure. In the period from when inside or continuous information becomes definite until its proper disclosure, trading by its holders or by their spouses, children or household members is a market-disrupting act (Art. 4(4)).

These rules work alongside the issuer’s disclosure duties. An issuer may delay disclosure of inside information, at its own responsibility, to protect its legitimate interests, provided the delay does not mislead investors and confidentiality can be maintained (Communiqué II-15.1 Art. 6(1)); during the delay it must control access to the information through the list of persons with access to inside information and other measures (Art. 6(3)). Issuers notify the Central Registry Agency (MKK) of employees and others who have regular access to inside information, and the list is sent to SPK and the exchange on request (II-15.1 Art. 7(1)). Persons with administrative responsibility are deemed to have access to inside information (Art. 7(2)). SPK can obtain these lists on request when it examines trading before an announcement. Disclosure duties are explained in the guide to continuous disclosure under Communiqué II-15.1.

The category of holders includes persons who hold the information “because they are shareholders” of the issuer or its subsidiaries or parents (Communiqué Art. 3(1)(ç)(2)). An institutional shareholder that receives non-public information through engagement with management, through a board nominee or in connection with a transaction may therefore come within Article 4. The blackout in Article 4(3) applies to holders of inside or continuous information, so whether an institution is within it depends on whether it in fact holds such information.

Order and transaction-based acts

Article 5 is the provision most often relevant to trading patterns. It has three parts. The conduct must be carried out on exchanges or other organised markets by persons alone or together with persons acting together. It must be capable of being regarded as significant or effective in the light of data on the functioning of the market or price formation, “such as prices, price changes, trading volumes, trade quantities, trade ratios, order quantities, order ratios, order cancellation quantities, order cancellation ratios or order execution ratios”. And it must disrupt the confident, transparent and stable functioning of markets, or create a false or misleading impression about prices, price changes, supply and demand, or make difficult or prevent fair and honest trading, the competitive functioning of the market or the accurate and honest formation of prices (Art. 5(1)).

Several features of Article 5 are important in practice. The significance test refers to market data such as prices, volumes, order ratios and cancellation ratios, so the analysis rests on these figures for the person and the period concerned. Limbs (d), (e) and (f) use the words “aimed at”, which introduces an element of direction or purpose in the conduct itself; the other limbs describe patterns objectively. The closing words “and similar transactions” indicate that the list is not intended to be closed. Finally, Article 5 applies to the conduct of a single person and to persons acting together, so whether accounts are linked under Article 3(1)(a) can decide whether the significance threshold is met.

For an investor who has suffered losses, an SPK finding under Article 5 identifies the accounts, the period and the type of pattern. These are the facts on which a later civil or criminal analysis is built. For the criminal offence of trade-based manipulation, the same patterns would need to be shown to have been carried out for the purpose of creating a false or misleading impression (Capital Markets Law Art. 107(1)); this is discussed in the guide to market manipulation.

Acts committed through communication

Article 6 deals with information. Its first two paragraphs were replaced in 2017.

1. 1. False or misleading information combined with trading. Giving false, wrong or misleading information, starting rumours, giving news, making special situation disclosures, commenting or preparing reports, in relation to capital market instruments’ prices or values, investors’ decisions or market indicators that may affect them, is a market-disrupting act where the persons who do so place any kind of order or trade in the relevant instrument before or after doing so (Art. 6(1)).
2. 2. Spreading it. Disseminating such information by persons who know, or should know, that it is false, wrong or misleading is a market-disrupting act where those persons place orders or trade in the relevant instrument before or after the dissemination (Art. 6(2)).
3. 3. Non-disclosure. Failing to disclose information that must be disclosed under SPK’s disclosure rules and that may affect the prices or values of capital market instruments or investors’ decisions is a market-disrupting act (Art. 6(3)).
4. 4. Trading against one’s own public recommendation. After giving a comment or recommendation about capital market instruments through newspapers, television, the internet or similar mass media, selling despite having recommended buying or holding, or buying despite having recommended selling, until the comment or recommendation is changed and in any event within five business days, is a market-disrupting act (Art. 6(4)).

The 2017 wording of Article 6(1) and (2) links the information to trading: it is the combination of the communication with orders or trades “before or after” that is caught. The criminal offence in Capital Markets Law Article 107(2) instead requires a purpose of affecting prices, values or investor decisions and that a benefit be obtained. Article 6(3) on non-disclosure is relevant to issuers whose disclosures lag behind events. A delay that meets the conditions of Communiqué II-15.1 Article 6 is permitted, and SPK may examine whether the reasons for a delay were justified (II-15.1 Art. 6(2)). Where the exchange asks an issuer to explain unusual price or volume movements, the issuer must make a public disclosure stating whether there are undisclosed special situations (II-15.1 Art. 8(1)). Social media promotion of shares, which often raises both Article 6 and Article 107(2), is discussed in the guide to social media stock manipulation.

Other market-disrupting acts

Article 7 collects four further acts.

• ▸ Front-running. With knowledge of investors’ order information, before orders of a size capable of affecting the price or value of an instrument are transmitted to investment firms, the exchange or other organised markets, placing, amending or cancelling orders in that instrument or in related instruments, or passing information about those orders to third parties (Art. 7(1)).
• ▸ Using another person’s account. Without authorisation by a power of attorney drawn up by a notary, using another person’s account to transmit orders, trade or carry out account movements, or letting another person use one’s account for these purposes (Art. 7(2)). Both the user and the account holder are caught. Where linked accounts were used by the same persons, Article 7(2) can apply alongside Article 5.
• ▸ Large shareholders’ sales without a share sale information form. Acting contrary to Article 27 of the Share Communiqué VII-128.1, or to SPK principle decisions on its application (Art. 7(3)).
• ▸ Trading while banned. Trading on exchanges or other organised markets, from one’s own account or others’ accounts, by persons subject to an SPK trading ban during the ban (Art. 7(4)).

Article 27 of Communiqué VII-128.1 is relevant to sell-downs by controlling shareholders. Where shareholders of a listed company who directly hold more than 20 per cent of its capital, alone or with persons acting together, or who hold privileged shares giving the right to elect or nominate at least one board member, intend to sell on the exchange shares exceeding 10 per cent of the capital in any twelve-month period, a share sale information form must be prepared and approved by SPK before the sale (VII-128.1 Art. 27(1)). The shareholder must make a special situation disclosure about the application at the latest before the session opens on the business day following the application; the approved form is published on KAP within five business days of approval; and the first sale may take place at the earliest on the third business day after publication (Art. 27(5)). Daily sales may not exceed 10 per cent of the total nominal value of the shares covered by the form, and the shareholder discloses the sales daily (Art. 27(6)). Wholesale transactions, special order sales, sales in liquidity provision or market making and secondary public offerings are outside the rule (Art. 27(8)), as are shares held by public bodies and Türkiye Wealth Fund, and certain other shares (Art. 27(9)). A controlling shareholder who sells large blocks into the market without following this procedure commits a market-disrupting act under Communiqué VI-104.1 Article 7(3). Issues on share issues and dilution are covered in the guide to capital increases and dilution.

What is not a market-disrupting act

Article 8 of the Communiqué, as replaced in 2017, provides that the following are not market-disrupting acts: the cases that are not insider dealing or market manipulation under Article 108 of the Capital Markets Law, activities within the scope of press freedom, and acts and transactions that do not fall within Article 104 of the Law.

Article 108 covers three situations: transactions by the Central Bank or another authorised official institution, or persons acting on their behalf, to implement monetary, exchange rate or public debt management policy or to safeguard financial stability; buy-back programmes, employee share programmes and other allocations of shares to employees carried out under SPK rules; and purchases or sales, or orders and cancellations, carried out solely to support the market price of instruments for a predetermined period, provided they comply with SPK’s rules on price stabilisation and market making. The buy-back safe harbour is narrower than it looks; the conditions are explained in the guide to share buy-backs.

The third exclusion, “acts and transactions that do not fall within Article 104”, brings the statutory test back into every case. Even where conduct matches a pattern listed in the Communiqué, it is not a market-disrupting act if it can be explained by a reasonable economic or financial reason, or if it is not of a nature to disrupt the confident, transparent and stable functioning of the market. The Misdemeanours Law adds that the Penal Code’s grounds of justification and grounds excluding fault apply to misdemeanours unless the Misdemeanours Law provides otherwise (Misdemeanours Law Art. 12).

SPK’s measures under Article 101

Article 101(1) of the Capital Markets Law allows SPK, in relation to natural or legal persons, and the authorised officers of legal persons, regarding whom there is reasonable suspicion that they have committed the acts listed in Articles 104, 106 and 107, and in relation to the capital market instruments concerned, to take any measure necessary to ensure the effective and sound functioning of the market. The Law lists:

1. (a) a temporary or permanent ban on trading on the exchanges;
2. (b) changes to settlement methods;
3. (c) restrictions on margin trading, short selling and securities lending and borrowing;
4. (ç) imposing or changing collateral requirements;
5. (d) trading in different markets or under different trading rules;
6. (e) limiting the distribution of market data;
7. (f) trading or position limits.

SPK is also authorised to set the procedures for applying these measures (Art. 101(1)). Article 104 was added to Article 101(1), and the heading of the article was changed to refer to market-disrupting acts, by Law No. 7518 of 26 June 2024 (Art. 10). Before that amendment, Article 101(1) referred only to insider dealing and market manipulation. The same law added Article 101(3): in examinations and inspections under Articles 104, 106 and 107, SPK may order the removal of content and/or the blocking of access to publications made over the internet, and its decision is sent to the Association of Access Providers for implementation.

These measures are based on reasonable suspicion, not on a finding that a market-disrupting act was committed. A trading ban therefore does not mean that the person has been fined or that a fine will follow. For investors, measures on a share (a move to a different market, a change to gross settlement or collateral requirements) affect liquidity and price. The exchange-level consequences, including the Watchlist Market and its trading rules, are explained in the guide to trading halts, the Watchlist Market and delisting.

How SPK examines trading

SPK’s professional staff are authorised to inspect the application of the Capital Markets Law and the capital market provisions of other laws and all capital market activities and transactions; this power is exercised by staff designated by SPK’s Chair (Capital Markets Law Art. 88(1)). Inspections cover all institutions within the Law’s scope and other natural and legal persons in respect of their capital market activities and transactions (Art. 89(1)). The inspectors may request information and documents, examine all books, records and information systems, including tax records and electronic records, take copies, inspect transactions and accounts, take written and oral statements and draw up reports (Art. 89(1)). The persons concerned must comply with these requests and sign the reports; a refusal to sign is recorded with its reasons (Art. 89(2)). On SPK’s Chair’s request and a criminal judgeship of peace’s decision, searches may be carried out with police assistance (Art. 89(3)).

Persons asked for information may not refuse by relying on confidentiality or secrecy provisions in the Law or special laws (Art. 90(1)). Persons under examination, and persons and institutions asked for information or documents about the matter, must keep the existence and nature of the examination secret (Art. 90(2)). A foreign institution whose Turkish broker or custodian receives an SPK request should bear in mind that the intermediary may be bound by this secrecy duty.

SPK may also cooperate with foreign regulators. It is authorised to exchange information and respond to document requests with equivalent foreign authorities on the basis of reciprocity and professional secrecy and to sign bilateral or multilateral memoranda of understanding (Art. 128(1)(d)). Trading by foreign accounts can therefore be examined with information obtained from the regulators of the jurisdictions concerned.

How to obtain SPK’s findings and the underlying documents for a civil or criminal case is discussed in the guide to obtaining and preserving evidence.

Administrative fines

Article 104(1) states the fine as a range, TL 20,000 to TL 500,000, in its statutory text. These are not current figures. Fixed-amount administrative fines are increased each calendar year by the revaluation rate determined and announced under the Tax Procedure Law, and this increase does not apply to proportional fines (Misdemeanours Law Art. 17(7)). The amounts applicable in a given year must therefore be calculated from the base amounts.

Article 105(2) is a special rule for repetition. Where a misdemeanour defined in the Capital Markets Law is committed more than once before an administrative sanction decision is made, a single fine is imposed under the relevant provision and doubled. Where a benefit was obtained or a loss caused, the fine may not be less than three times that benefit or loss. Under the general rule, by contrast, each repetition of the same misdemeanour attracts a separate fine, and a continuing act counts as one until a decision is made (Misdemeanours Law Art. 15(2)). For a trading pattern spread over weeks or months, the way SPK groups the conduct into one or several acts therefore affects the amount.

The benefit is central both to the floor in Article 104 and to Article 105(2). How SPK calculated the benefit, which trades and prices it used, and whether costs and losses on other trades were taken into account, can be central points in a challenge.

Limitation periods

The Capital Markets Law does not contain a separate limitation rule for Article 104, so the Misdemeanours Law applies. Once the investigation limitation period has expired, no administrative fine may be imposed (Misdemeanours Law Art. 20(1)). The period is five years for misdemeanours requiring a fine of TL 100,000 or more, four years for TL 50,000 or more, and three years for less than TL 50,000; for misdemeanours requiring a proportional fine it is eight years (Art. 20(2)–(3)). The period starts when the act defined in the misdemeanour is committed or the result occurs (Art. 20(4)). Where the act also constitutes a crime, the criminal limitation rules apply (Art. 20(5)).

Applying these bands to Article 104 is not straightforward. The Article sets a range rather than a single amount, and the benefit-linked floor adds a proportional element. Which band applies is a question to be argued on the facts and the wording of the decision, and it is the subject of discussion in Turkish legal writing. Once a fine has been imposed, a separate enforcement limitation period applies, ranging from three to seven years depending on the amount of the fine (Art. 21(2)).

For investors’ own deadlines, which are different and often shorter, see the guide to limitation periods for investor claims.

The defence stage

Before an administrative fine is imposed, the person concerned must be asked for a defence. If no defence is submitted within thirty days of service of the written request, the person is deemed to have waived the right of defence (Capital Markets Law Art. 105(1)). This is the most important procedural stage. The answer becomes part of the file that the administrative court will later review, so it should deal with each item of conduct, each period and each instrument identified in SPK’s request.

A defence will usually need to address five questions: whether the conduct falls within a specific definition in Communiqué VI-104.1; whether it can be explained by a reasonable economic or financial reason; whether it was capable of disrupting the market, given the data relied on; whether the person is correctly linked to other accounts as a person acting together; and whether the benefit, if any, is correctly calculated. Limitation and the possible criminal character of the conduct are threshold points.

Challenging a fine or a measure in court

Fines imposed under the Capital Markets Law can be challenged before the administrative courts (Art. 105(4)), and administrative actions against SPK decisions are heard by the administrative courts and treated as urgent matters (Art. 134(1)). The general route under the Misdemeanours Law, an application to a criminal judgeship of peace within fifteen days (Misdemeanours Law Art. 27(1)), does not apply, because the Misdemeanours Law’s provisions on remedies apply only where other laws do not provide otherwise (Art. 3(1)(a)).

The action for annulment must be filed within sixty days, unless a special law provides a different period (Administrative Procedure Law No. 2577 Art. 7(1)), starting from the day after written notification (Art. 7(2)(a)). Before filing, the person may ask the higher authority or, if there is none, the authority that made the decision to withdraw or change it within the period for filing; this stops the period, and if no answer is given within thirty days, the request is deemed rejected (Art. 11). Unless a law provides otherwise, the competent administrative court is the one where the authority that made the decision is located (Art. 32(1)). The Capital Markets Law places SPK’s head office in Istanbul, but keeps it in Ankara until the move to Istanbul is completed (Arts. 117(1) and Provisional Art. 7(5)).

Filing an action does not suspend the decision (Administrative Procedure Law Art. 27(1)). The court may order a stay of execution, with reasons, if the implementation of the decision would cause damage that is difficult or impossible to remedy and the decision is clearly unlawful, both conditions being met, after the authority’s response is received or the time for it has passed (Art. 27(2)). For a trading ban, the effect on the person’s activities can be the basis of the irreparable-harm argument.

Actions against SPK, including full remedy actions for losses said to result from its decisions or failures, are explained in the guide to suing the Capital Markets Board.

What Article 104 findings mean for investors

An SPK decision that a person committed a market-disrupting act is an administrative decision, not a court judgment, and it is not a criminal conviction. It can still be important evidence. It identifies the conduct, the accounts, the instruments and the period, and it records SPK’s assessment of the market data. A person who causes loss to another by an unlawful and culpable act must compensate it (Turkish Code of Obligations No. 6098 Art. 49(1)). An investor relying on SPK’s finding must still prove its own loss and the causal link between the conduct and that loss, and the civil court assesses fault itself: under Article 74 of the Code of Obligations even a criminal court’s assessment of fault and determination of damage do not bind the civil judge. The methods for quantifying losses are discussed in the guide to calculating damages.

Three further points are relevant to investors:

• ▸ The administrative and criminal tracks are linked. SPK may treat some conduct as a crime and apply to the prosecutor under Article 115, and other conduct as market-disrupting. Where a criminal case follows, an investor who has suffered harm can take part in the criminal process, as explained in the guide to joining a criminal case.
• ▸ Issuer non-disclosure is itself a listed act. A finding under Communiqué Article 6(3) that an issuer failed to disclose price-sensitive information supports a disclosure liability analysis under Capital Markets Law Article 32, discussed in the guide to prospectus and disclosure liability.
• ▸ Investors may bring facts to SPK’s attention. There is no statutory form for this, but a well-documented request can prompt SPK to examine trading under Articles 104 and 107 and to consider measures under Article 101.

Compliance points for institutional investors

The breadth of the Communiqué means that a foreign institution trading in Turkish shares should check its own arrangements against it. The points below follow the text of the Communiqué; they are not a substitute for advice on a specific structure.

1. 1. Persons acting together. The definition includes persons using the same premises, virtual environment, computer, telephone, internet connection or communication channel (Art. 3(1)(a)(6)). Where several funds, sub-funds or managers within a group trade the same Turkish share through shared infrastructure, independent decision-making and the reasons for each order should be documented.
2. 2. Accounts used by others. Article 7(2) refers to authorisation by a notarised power of attorney where orders are placed on another person’s account. Mandate and authorisation documents for accounts held in Turkey should be checked against this wording.
3. 3. Information from issuers. Persons holding inside or continuous information because they are shareholders are covered (Art. 3(1)(ç)(2)). Engagement meetings, board nominees and transaction discussions can bring the institution within the tipping rule in Art. 4(2) and the trading windows in Art. 4(3) and (4).
4. 4. Order behaviour. Algorithms and execution strategies should be reviewed against Article 5, in particular direction-switching orders within less than a minute (Art. 5(1)(c)), orders in the opening and closing sessions (Art. 5(1)(d)) and cancellation ratios.
5. 5. Public comments. Portfolio managers who comment on Turkish shares in the media should note the five-business-day rule in Article 6(4).
6. 6. Large positions. Holders of more than 20 per cent, or of board nomination privileges, need an approved share sale information form before selling more than 10 per cent of the capital on the exchange in twelve months (VII-128.1 Art. 27).
7. 7. Records and requests. SPK may request information and documents and may not be refused on confidentiality grounds (Capital Markets Law Arts. 89 and 90(1)); the existence of an examination must be kept secret (Art. 90(2)). A procedure for responding to requests received through Turkish intermediaries should be in place.

Liability of brokers, custodians and portfolio managers to their clients is a separate subject, covered in the guide to claims against brokers, custodians and portfolio managers.

Time limits

Frequently asked questions

What is a market-disrupting act under Turkish law?

An act or transaction that cannot be explained by a reasonable economic or financial reason and that disrupts the confident, transparent and stable functioning of exchanges and other organised markets, where it does not constitute a crime (Capital Markets Law Art. 104(1)); SPK has listed these acts in Communiqué VI-104.1.

Is a market-disrupting act a crime?

No. It is an administrative offence sanctioned by an SPK fine. If the conduct constitutes a crime, such as market manipulation or insider dealing, Article 104 does not apply.

What fine applies?

The Law sets a range (base amounts TL 20,000 to TL 500,000), increased annually by the revaluation rate (Misdemeanours Law Art. 17(7)); where a benefit was obtained, the fine may not be less than twice the benefit.

Does SPK have to prove intent?

Article 104 and the Communiqué do not require intent, and misdemeanours may be committed intentionally or negligently unless the law provides otherwise (Misdemeanours Law Art. 9); some limbs of Article 5 use the words “aimed at”.

Can SPK ban trading before it imposes a fine?

Yes. Since Law No. 7518 of 2024, SPK may take measures under Article 101(1), including trading bans, where there is reasonable suspicion of market-disrupting acts.

What is the blackout period in Communiqué VI-104.1?

From the day after the end of the accounting period until the financial statements and reports are disclosed, holders of inside or continuous information and their spouses, children and household members may not trade in the relevant instruments (Art. 4(3)).

Is using another person’s account a market-disrupting act?

Yes, unless authorised by a notarised power of attorney; both the user and the account holder are caught (Communiqué VI-104.1 Art. 7(2)).

How long does a person have to respond to SPK?

Thirty days from service of the request for a defence; otherwise the right of defence is deemed waived (Capital Markets Law Art. 105(1)).

Where is an SPK fine challenged?

Before the administrative courts (Capital Markets Law Arts. 105(4) and 134(1)), within sixty days of notification (Administrative Procedure Law Art. 7).

Can investors use an SPK finding in a damages claim?

It can be important evidence of unlawful conduct, but the investor must still prove loss and causation, and the civil court assesses fault itself (Code of Obligations Arts. 49 and 74).

Related guides

• Turkey’s 2026 Fund and Market Manipulation Crisis: Legal Guide for Foreign Institutional Investors — the entry point to this series
• Borsa Istanbul Trading Rules: The Equity Market Directive
• Criminal Code Offences in Turkish Capital Markets Cases
• Investment Services Rules in Turkey: Communiqués III-37.1 and III-39.1
• Public Offerings in Turkey: Prospectus, Price Determination Report, Allocation and Stabilisation
• Turkish Investment Fund Rules: Communiqués III-52.1, III-55.1 and III-56.1
• Market Manipulation under Turkish Law: Article 107
• Insider Dealing in Turkey: Article 106
• Social Media Stock Manipulation and Unlicensed Investment Advice
• Continuous Disclosure in Turkey: Communiqué II-15.1
• Suing the Capital Markets Board in Turkey
• Share Buy-Backs in Turkey: Communiqué II-22.1
• Trading Halts, Watchlist Market and Delisting on Borsa Istanbul
• Financial Reporting Fraud and Audit Failures in Turkish Listed Companies
• Obtaining and Preserving Evidence in Turkey for Securities Claims
• Limitation Periods for Investor Claims in Turkey