Can Foreign Investors Bring a Class Action in Turkey? Joint Claims, Consolidation, Association Actions and Assignment

When many foreign funds suffer losses in the same Turkish market event, their counsel usually ask whether a class action is possible. The short answer is that Turkish law has no opt-out class action for damages: every investor who wants compensation has to be a claimant, directly or through someone to whom it has assigned its claim. Turkish procedure does, however, give investors several ways to act together. Claimants whose cases rest on the same or similar facts may sue jointly; related cases may be consolidated in one court; associations may bring collective actions for declaratory and preventive relief, though not for damages; and claims may be assigned in writing to a single vehicle. This guide explains each tool, how claims are quantified after the 2026 repeal of the unquantified claim, how costs and court fees are allocated, how mandatory mediation and limitation apply, and why a judgment for one investor does not decide the claims of others. It reflects the legislation in force as at 25 October 2026.

The short answer

Turkish civil procedure is built around the individual claimant. A court decides only the claims of the parties before it, and a final judgment binds, as a rule, only those parties and their universal successors (Code of Civil Procedure Art. 303). There is no mechanism by which one investor, or a lead plaintiff, can sue for damages on behalf of an open class of investors who have not themselves become parties, and no opt-out procedure through which absent investors are bound unless they withdraw.

That does not mean every fund must litigate alone. Turkish law offers five practical ways of coordinating claims arising from the 2026 market manipulation and fund cases, which are explained below: joint claims, consolidation, association actions, assignment of claims to one vehicle, and coordinated participation in the criminal case. For unit holders of the liquidated funds there is, in addition, the collective recovery mechanism of the new fund law, discussed in our fund liquidation guide. The wider map of routes and deadlines is in our legal guide for foreign institutional investors.

The tools compared

Joint claims by several investors

Several persons may sue together, or be sued together, where the right or obligation at issue is common to them otherwise than through joint ownership, where a right has arisen for all of them or an obligation has been assumed by all of them through a common transaction, or where the facts and legal grounds on which the claims are based are the same or similar (Code of Civil Procedure Art. 57(1)(a)–(c)). The third ground is the one that fits investor claims: funds that bought the same shares in reliance on the same prospectus or announcements, or that suffered losses from the same manipulation scheme, bring claims based on similar facts and the same legal grounds.

This form of joinder is optional, and the law spells out its main consequence: the claims remain independent of each other, and each claimant acts independently of the others (Art. 58(1)). In practice:

• each investor must prove its own loss and the causal link between the defendant’s conduct and that loss, although disclosure claims benefit from presumed causation in qualifying cases (Capital Markets Law Art. 32(4));
• each investor’s claim has its own value, which must be stated in the petition (Code of Civil Procedure Art. 119(1)(d));
• each investor’s limitation period runs separately, and one claimant’s filing does not interrupt limitation for another;
• one claimant may settle or withdraw without affecting the others;
• each investor needs its own power of attorney (Arts. 74 and 76).

Where several defendants are sued together, the claim may be brought in the court of the domicile of any one of them, unless the law gives one court common venue over all of them (Art. 7(1)); a defendant brought there solely to move it away from its own court may object and have its case separated (Art. 7(2)). For tort claims, the court of the place where the act was committed or the loss occurred is also competent (Art. 16).

Consolidating related cases

Investors who have already sued separately, or who sue at different times, can ask for their cases to be heard together. Cases pending before courts of the same level and type in the same judicial district may be consolidated, at any stage, on request or by the court of its own motion, in the court where the first case was filed; that court is bound by the consolidation decision once it becomes final (Code of Civil Procedure Art. 166(1), as amended by Law No. 7589). Where the cases are in different judicial districts, consolidation on grounds of connection may be requested from the court of the second case, and the court of the first case is bound by a final decision granting it (Art. 166(2)).

Cases are deemed connected where they arise from the same or similar causes, or where the judgment in one would affect the other (Art. 166(4)). Claims by different investors arising from the same manipulation scheme or the same misleading disclosure meet this test in the ordinary case.

Consolidation does not merge the claims. Each consolidated case keeps its own parties, value and limitation position, and the court may separate them again if hearing them together hinders the proceedings (Art. 167(1)).

Collective actions by associations

Associations and other legal entities may, within the scope of their statutes, sue in their own name to protect the interests of their members, of those affiliated with them or of the section of the public they represent (Code of Civil Procedure Art. 113(1)). The relief is limited by the text to three things: a declaration of the rights of those concerned, removal of an unlawful situation, or prevention of future infringement of their rights.

Two limits follow from that wording. First, an association cannot obtain damages for its members through this procedure; compensation must still be claimed by each investor, or by an assignee. Second, the association must be one whose statute covers the protection of the group concerned. For investors, an association action is therefore a tool for establishing principles, for example a declaration of rights arising from the same conduct, rather than a route to payment. It may be useful alongside individual damages claims, but it does not replace them.

Bundling claims by assignment

The closest Turkish equivalent to a single vehicle bringing many investors’ claims is the assignment of claims. A creditor may assign its claim to a third party without the debtor’s consent, unless the law, the contract or the nature of the transaction prevents it (Turkish Code of Obligations Art. 183). The assignment is valid only if made in writing (Art. 184). With the claim, the preferential and accessory rights pass to the assignee, other than those personal to the assignor, together with accrued interest (Art. 189). The assignor must hand over the documents evidencing the claim and give the information needed to enforce it (Art. 190).

The defendant is not prejudiced by the assignment. It may raise against the assignee the defences it had against the assignor when it learned of the assignment (Art. 188). Each assigned claim therefore remains subject to its own facts, causation and limitation. A foreign assignee suing in Turkey must also expect to give security for costs unless exempted on reciprocity (Law No. 5718 Art. 48).

What each investor must prove

Coordinated litigation saves cost and effort on the common questions: what the defendants did, whether the disclosures were misleading, how prices moved. It does not remove the individual elements of each claim, which differ by route.

The burden of proving the loss and the defendant’s fault lies on the claimant; where the exact amount of the loss cannot be proved, the judge determines it equitably, considering the ordinary course of events and the steps the injured party took (Turkish Code of Obligations Art. 50). Agreements or statements that limit or exclude liability for public disclosure documents are void (Capital Markets Law Art. 32(7)).

Proving holdings held through custodians

Foreign institutions usually hold Turkish shares through global custodians and local sub-custodians. Dematerialised capital market instruments are monitored in accounts opened in the holder’s name, although SPK may allow accounts to be kept collectively without opening an account in the right-holder’s name, depending on the type of instrument and the issuer or member concerned (Capital Markets Law Art. 13(2)). The rights attached to such instruments are monitored by the Central Registry Agency (MKK), and the records are kept by its members in the electronic system it operates (Art. 13(3)).

For group litigation, this means each claimant must be able to show its own position: what it bought or sold, when, at what price and through which account. The evidence is usually a combination of the investor’s trade records, custody statements down the chain and, where needed, records held by intermediaries. A Turkish court can order a party to produce a document that is necessary to prove an allegation; if the party fails to produce it without a valid excuse, the court may accept the other side’s account of its contents (Code of Civil Procedure Art. 220(1) and (3)). It can also order a third party or institution holding such a document to produce it (Art. 221(1)–(2)).

Expert evidence across many claims

Price effects, trading patterns and loss calculations are technical questions. Courts obtain expert opinions where a matter requires special or technical knowledge outside law, on a party’s request or of their own motion (Code of Civil Procedure Art. 266(1)). As a rule a single expert is appointed, but the court may, giving reasons, appoint a panel of an odd number of experts (Art. 267(1)). When claims are brought jointly or consolidated, one expert examination can address the common questions for all claimants, with individual calculations for each investor. That is one of the main practical advantages of litigating together.

Quantifying claims after the 2026 reform

Investor losses are rarely fixed at the start of a case. Until 2026 Turkish procedure offered the unquantified claim (belirsiz alacak davası) for such situations. Law No. 7589 repealed that provision (Code of Civil Procedure Art. 107) and added a new rule to the partial claim (Art. 109(4)). The present position is:

• where the subject matter is divisible, a claimant may sue for part of it (Art. 109(1));
• filing a partial claim does not mean the rest is waived, unless the claimant expressly waives it (Art. 109(3));
• where only part of a claim was filed, the claimant may increase it once in the same case, until the end of the investigation stage, without being bound by the prohibition on expanding the claim, and limitation for the increased part is treated as interrupted from the date the case was filed (Art. 109(4)).

Separately, each party may amend its procedural acts once in the same case (Art. 176), until the end of the investigation stage (Art. 177(1)). For investor claims the partial claim with a later increase is now the natural way to start a case while the evidence on quantum, often expert evidence on prices and trading, is still being gathered. Starting with a modest amount also limits the advance court fee, which is calculated on the amount claimed.

Costs, court fees and security

In a joint claim each investor’s claim is valued separately, so fees and costs are calculated on each claim, and costs are allocated according to the result of each claim. In an assignment structure the assignee bears the fees and the costs risk for the whole bundle.

Mandatory mediation

In commercial cases whose subject is a sum of money, including claims for receivables and compensation, applying to a mediator before suing is a condition of the action (Turkish Commercial Code Art. 5/A(1)). The mediator must conclude within six weeks of appointment, extendable by up to two weeks where necessary (Art. 5/A(2)). The application suspends limitation (Law No. 6325 Art. 18/A(15)).

Whether a given investor claim is a commercial case depends on its basis. Disputes arising from matters regulated in the Commercial Code, such as claims against directors and managers (Commercial Code Art. 553), are commercial cases whatever the status of the parties (Art. 4(1)(a)); other claims are commercial where both parties’ commercial enterprises are concerned (Art. 4(1)). Where several investors claim jointly, each investor’s relationship with each respondent has to be considered, and the power of attorney must expressly authorise recourse to mediation (Code of Civil Procedure Art. 74).

What a judgment for one investor decides

A final judgment has binding effect in another case only where the parties, the cause of action and the relief are the same (Code of Civil Procedure Art. 303(1)). A judgment won by one fund against a defendant does not, therefore, decide the claims of other funds against the same defendant, even on the same facts. It can be highly persuasive, and the findings and expert evidence in it can be used as evidence in later cases, but each investor must still establish its own claim.

Investors sometimes consider letting one “test case” run first. Turkish procedure allows a court to stay a case whose outcome depends in whole or in part on another case (Art. 165(1)). A stay does not, however, protect claims that have not been filed. Limitation keeps running against every investor who has not sued, so a test-case strategy works only if the other investors file their own claims, at least as partial claims, and ask for them to be stayed or consolidated.

Many victims in the criminal case

In the criminal process, too, participation is individual. Each person harmed by the offence may join the public prosecution as a participating party until judgment at first instance (Criminal Procedure Code Art. 237), and each participating party may use appeals independently of the prosecutor (Arts. 242 and 260). A single lawyer may act for several victims, and coordinated participation allows investors to share the work of following the file, requesting evidence and objecting to decisions. Participation is explained in Joining a Criminal Case in Turkey as a Foreign Investor.

The criminal court does not award investors damages. Damages are claimed in the civil courts, through the joint, consolidated or assigned claims described above, and securing assets for those claims is explained in Freezing Assets in Turkey for Investor Claims.

Unit holders: a collective mechanism already exists

For investors who held units in one of the 131 funds SPK ordered into liquidation on 17 September 2026, the position is different. Law No. 7596, approved by parliament on 22 October 2026 and awaiting publication in the Official Gazette, creates a collective regime for those funds. According to the approved text as reported, it provides for interim payments of up to TL 1 million per investor per fund on an inflation-adjusted net-investment basis (Art. 4), makes the portfolio management company primarily liable for fund losses, followed by the persons SPK identifies (Art. 5), and directs assets seized or confiscated in fund-related investigations to the funds or to recovery accounts held for their unit holders (Art. 6).

That regime works for unit holders as a group without each of them suing, but it covers only the liquidated funds. Shareholders of the listed companies whose shares were manipulated are outside it and must use the individual and coordinated civil claims described in this guide.

A practical sequence for a group of investors

1. Identify the common defendants and routes. Map each investor’s positions against the shares, persons and periods named in SPK bulletins and against issuer disclosures, and decide which routes apply: disclosure liability, tort, directors’ liability.
2. Check each investor’s deadlines. The six-month disclosure period runs from each investor’s own loss (Capital Markets Law Art. 32(6)); tort and directors’ claims have their own periods (Turkish Code of Obligations Art. 72; Turkish Commercial Code Art. 560).
3. Choose the structure. Joint claim, separate claims to be consolidated, or assignment to one vehicle; consider an association action only for declaratory or preventive relief.
4. Prepare powers of attorney and security. Notarised and, where signed abroad, apostilled powers covering settlement and mediation (Code of Civil Procedure Arts. 74 and 76); security for costs for foreign claimants (Law No. 5718 Art. 48).
5. Secure assets. Where defendants may move assets, a precautionary attachment may be needed before the lawsuit (Enforcement and Bankruptcy Law Art. 257).
6. Mediate where required, then file. Mediation where the claim is a commercial money claim (Turkish Commercial Code Art. 5/A), then a partial claim to be increased once the expert evidence is in (Code of Civil Procedure Art. 109(4)).
7. Coordinate with the criminal case. Each investor that wants to participate files its own application (Criminal Procedure Code Art. 237), and the evidence in the criminal file is used in the civil claims.

Settling group claims

Because the claims in a joint or consolidated case remain independent, settlement is also individual. A settlement in court is a contract by which the parties end their dispute in whole or in part; it may be made only on matters the parties can freely dispose of, may include matters outside the case and may be conditional (Code of Civil Procedure Art. 313). It can be made at any time until the judgment becomes final (Art. 314(1)). It ends the case to which it relates and has the effect of a final judgment, and it may be set aside for defects of consent or excessive advantage (Art. 315). One investor’s settlement therefore ends that investor’s claim only; the others continue.

Settlements reached in mediation have their own rules. The parties may ask the court for an annotation confirming that the mediation agreement is enforceable, which gives it the status of a document having the force of a judgment (Law No. 6325 Art. 18(2)). In commercial disputes, an agreement signed by the parties’ lawyers and the mediator has that status without the annotation, except where the law requires one (Art. 18(4)). Once agreement is reached, no lawsuit can be brought on the matters agreed (Art. 18(5)). For a group of investors negotiating with a defendant, this allows a common settlement framework to be implemented through individual agreements with each claimant.

Deadlines for each claimant

Because joint claims and assignments do not merge the underlying claims, each of these periods has to be checked for each investor, and for each claim, separately. A group that waits until all members have agreed on a structure may find that the six-month period for disclosure claims has passed for some of them.

Frequently asked questions

Is there a securities class action in Turkey?

Not in the sense of an opt-out class action for damages. Each investor seeking compensation must be a party to the case, directly or through an assignee, and a judgment binds only the parties (Code of Civil Procedure Art. 303).

Can several foreign funds file one lawsuit together?

Yes. Investors whose claims rest on the same or similar facts and legal grounds may sue jointly (Art. 57(1)(c)). Their claims remain independent, and each investor proves its own loss (Art. 58).

Can separate lawsuits be heard together?

Yes. Connected cases may be consolidated in the court where the first case was filed, at any stage, on request or by the court of its own motion (Art. 166).

Can an investor association claim damages for its members?

No. An association may sue in its own name only for a declaration of rights, removal of an unlawful situation or prevention of future infringements (Art. 113). Damages are claimed by the investors or by an assignee.

Can claims be transferred to one company that sues for everyone?

Yes. Claims may be assigned in writing without the defendant’s consent (Turkish Code of Obligations Arts. 183 and 184). The defendant keeps the defences it had against each assignor (Art. 188).

Can an investor still bring an unquantified claim?

No. The unquantified claim was repealed by Law No. 7589. A partial claim may now be increased once, until the end of the investigation stage, with limitation for the increase treated as interrupted from the filing date (Code of Civil Procedure Art. 109(4)).

Does one fund’s lawsuit stop limitation for the others?

No. Limitation is interrupted only for the claimant who sues. Every investor must file in time, even if a test case is running.

How does a fund prove it held the shares?

Through its trade records and custody statements down the custody chain. Book-entry instruments are monitored by the Central Registry Agency and recorded by its members (Capital Markets Law Art. 13(3)), and the court can order parties or third parties to produce necessary documents (Code of Civil Procedure Arts. 220 and 221).

Can a foreign fund and a Turkish investor sue together?

Yes. Joinder depends on the claims resting on the same or similar facts and legal grounds, not on nationality (Code of Civil Procedure Art. 57). The foreign claimant may have to give security for costs unless exempted on reciprocity (Law No. 5718 Art. 48).

Where can a group of investors sue several defendants together?

In the court of the domicile of any one of the defendants (Code of Civil Procedure Art. 7(1)), or, for tort claims, where the act was committed or the loss occurred (Art. 16).

Who pays the court fees in a joint claim?

Fees are calculated on each investor’s claim, and the costs of the proceedings are borne by the losing party, or shared in proportion to success (Code of Civil Procedure Art. 326).

Related guides

• Turkey’s 2026 Fund and Market Manipulation Crisis: Legal Guide for Foreign Institutional Investors — the entry point to this series
• Turkish Bond Defaults: Bondholders’ Boards and Enforcement
• Continuous Disclosure in Turkey: Inside Information and Delayed Disclosure
• How a Securities Lawsuit Proceeds in Turkey
• Limitation Periods for Investor Claims in Turkey
• Concealed Profit Transfers and Controlling Shareholder Liability
• Claims Against Brokers, Custodians and Portfolio Managers in Turkey
• When a Turkish Issuer or Broker Becomes Insolvent
• Obtaining and Preserving Evidence in Turkey for Securities Claims — preservation, document production and the criminal file
• Shareholder Rights in Turkish Listed Companies after the 2026 Crisis — general meetings, release, annulment and exit rights
• Insider Dealing in Turkey: Capital Markets Law Article 106 — trading on non-public information
• Calculating Damages in Turkish Securities Claims — loss, interest and currency
• Suing in Turkey or Abroad: Jurisdiction and Enforcement — forum choice and enforcement of foreign judgments and awards
• Suing Turkey’s Capital Markets Board (SPK) — challenging SPK decisions and supervisory failure claims
• Suing Directors and Auditors of Turkish Listed Companies — board members, managers and audit firms
• Freezing Assets in Turkey for Investor Claims — precautionary attachment, interim injunctions and criminal seizure
• Norway’s Wealth Fund and Turkey’s Market Manipulation Crisis
• Prospectus and Disclosure Liability in Turkey: Articles 10 and 32
• Market Manipulation under Turkish Law: Article 107 and SPK Enforcement
• Joining a Criminal Case in Turkey as a Foreign Investor
• Representing Foreign Institutional Investors in Turkish Capital Markets Disputes
• Turkey’s 2026 Fund Liquidation: Legal Guide for Foreign Investors and Companies
• Legal Guide for Foreign Investors in Turkey (Türkiye) 2026
• Norveç Varlık Fonu “Mağduruz” Dedi — Turkish-language analysis (in Turkish)