1. What Was Manipulated?

EURIBOR - Euro Interbank Offered Rate: Index published each business day based on quotes each panel bank provides of rates at which they believe a hypothetical bank would lend. Calculated by averaging rates offered daily by 44 panel banks after eliminating highest and lowest 15%.

The Cartel - Case AT.39914 Euro Interest Rate Derivatives - EIRD:

European Commission found single and continuous infringement of Art.101 TFEU and Art.53 EEA Agreement between approx Sept 2005 and May 2008.

• 4 Dec 2013 Settlement Decision: Barclays, Deutsche Bank, RBS, Société Générale accepted facts - fined total €1.49 billion.
• 7 Dec 2016 Decision: Crédit Agricole, HSBC, JPMorgan Chase - non-settling - fined €485 million.

Conduct: traders exchanged sensitive information to manipulate Euribor submissions to benefit their Euro Interest Rate Derivatives positions. Not primarily to increase mortgage rates, but to increase derivative profits.

Estimation in Spanish academic study: coefficient for Cartel dummy on 12-month Euribor = 0.0705% = 7.05 basis points monthly overcharge. Small per mortgage, huge systemically.

2. Why Spain Is Epicentre

95% of Spanish mortgages are variable rate, vast majority indexed to 12-month Euribor. Any manipulation directly inflates cuota mensual.

Spain also had alternative IRPH - Índice de Referencia de Préstamos Hipotecarios - calculated from banks' own mortgage rates, itself held manipulable. European authorities imposed substitution of IRPH-Banks and IRPH-Savings Banks as they considered calculation method open to manipulation.

3. Two Different Legal Actions in Spanish Courts

Spanish jurisprudence, summarized by Cuatrecasas, divides claims into:

Group 1: Invalidity of Interest Rate Clause
Claiming clause referencing Euribor is null as abusive or contrary to good faith.

Group 2: Damages Action - Acción de daños por sobrecargo
Claiming overcharge paid as result of anticompetitive conduct under Ley 15/2007 Defensa de la Competencia and Art.101 TFEU.

Group 1: Almost Universally Dismissed

Doctrine of Palma de Mallorca Provincial Court 288/2016, 13 Oct:
"It is necessary to differentiate between events that motivated sanctions and alleged invalidity of clause that takes it as reference... (i) reference rate does not alter balance of benefits, (ii) Commission investigation did not declare effective deviation of Euribor, (iii) if manipulation occurs, what is appropriate is not to declare unfairness of clause, but at most to challenge settlement as breach of contract."

Followed by:

• Seville Provincial Court Sec 5, 347/2018, 12 June: Effective impact not demonstrated. Cannot approve erroneous calculation to detriment of borrower to justify invalidity.
• Valladolid Provincial Court Sec 1, 83/2021, 8 June: Same.
• Málaga Provincial Court Sec 6, 650/2019, 9 July: Invalidity not appropriate channel for recovering damages.
• Madrid Provincial Court Sec 14, Order 33/2015, 18 Feb: In foreclosure context, identifies potential victims but says they must prove extent of harm. Later confirmed in judgments 112/2020, 1939/2020, 80/2021.
• Valencia Provincial Court Sec 9, 964/2016, 30 Nov: Same.

Legal Reasoning: Euribor clause is not abusive under Directive 93/13. It is a core term defining price, based on official index published by Banco de España, not unilaterally set by lender. Manipulation, if any, is breach of how index should have been calculated, not unfair term.

Group 2: Damages - Stand Alone Action - Much Harder to Prove

After Group 1 failed, claimants shifted to competition damages, inspired by Trucks cartel AT.39824.

Key doctrinal battle: Follow-on vs Stand-alone

• Follow-on = infringement proven by Commission decision, claimant only proves causation and quantum.
• Stand-alone = claimant must prove infringement itself.

Palencia Provincial Court Sec 1, 84/2022, 9 Feb: First second instance to rule on merits. Concludes Euribor damages action must be considered stand-alone action in which anti-competitive infringement cannot be directly proven by Commission decisions, but must be proven by claimant itself, as they refer to a market other than mortgage credit market. Upholds dismissal for lack of proof.

Madrid Commercial Court 15, 24 Sep 2021: "There is no decision of the European Commission stating that there has been manipulation of the EURIBOR in the mortgage market with harmful effects for consumers."

Girona Provincial Court Sec 1, 221/2022, 9 Mar: Highlights information exchanges intended to influence derivatives, not only upwards, and exchanges by only 7 of 44 panel banks, so damage not proven.

Barcelona Commercial Courts Split:

• Commercial Court 12, 151/2021, 27 July and 380/2021, 21 Dec: Dismissed for lack of proof.
• Commercial Court 3, 757/2021, 758/2021, 759/2021 of 26 July and Court 7, 375/2021, 21 July: Consider damage proven based on Commission decision + expert report, but conclude damage minimal, partially uphold claims.

Barcelona Provincial Court Sec 15, 1138/2022 and 1202/2022, 11 and 15 July: Decides appeals against above. Applies CJEU C-267/20 Volvo of 22 June 2022 on limitation. Holds actions not time-barred, 5-year period Art.74 Ley 15/2007 Defensa de la Competencia applies. But on harm: claimant expert does not prove how sanctioned conduct influenced market other than affected one and defendant's expert "provides sufficient information and data from which to deduce that exchange of information in market for interest rate derivatives denominated in Euros did not have impact on formation of 12-month Euribor". Revokes 759/2021 and confirms dismissal.

4. Prescription and Procedural Issues

• Time-barring: Before Directive 2014/104/EU transposition, Spanish law applied 1-year art.1968 CC. After transposition via Real Decreto-ley 9/2017, art.74 Ley 15/2007 sets 5-year limitation. Barcelona Provincial Court applied 5 years retroactively via CJEU Volvo doctrine.

Question referred to CJEU by Barcelona Commercial Court 11, order 17 Feb 2022, on limitation, still pending.

• Burden of Proof: Claimant must prove:
  a) Cartel affected 12-month Euribor specifically, not just derivatives
  b) Effect was upward during his mortgage period
  c) Quantification - expert report using synthetic Euribor

Banks' defence: trimming 15% highest/lowest quotes dilutes manipulation, manipulation was both up and down, 7 banks insufficient to move average.

5. Parallel: IRPH Manipulation - More Successful for Borrowers

IRPH litigation offers contrast.

STS 669/2017, 14 Dec 2017: Supreme Court said transparency of IRPH clause cannot be reviewed because it is official index - declared legal and transparent.

CJEU C-125/18 Gómez del Moral Guasch, 3 March 2020 - Grand Chamber: Spanish courts must verify if IRPH clause is plain and intelligible. If unfair, may replace it to protect consumer. Transparency requires lender explain how IRPH calculated and how it differs from Euribor.

CJEU C-300/23, 2024 and STS 1590/2025 and 1591/2025, 11 Dec 2025 - Plenary: Supreme Court finally accepts transparency control for IRPH. Must compare to real average market rates from Bank of Spain, INE, not simply to Euribor. Transparency fails if bank did not provide pre-contractual FIPER explaining that IRPH = average of banks' rates + costs, therefore inherently higher and less volatile, and not comparable to Euribor.

Result: Many IRPH clauses declared non-transparent and replaced by Euribor + differential, with restitution.

This shows difference: IRPH manipulation claim succeeded via transparency route, Euribor via cartel route failed due to proof gap.

6. Current Legal Implications for Mortgage Contract

For a Spanish mortgage today with Euribor manipulation allegation:

Nullity will be rejected per Seville, Valladolid, Palma doctrine.

Damages possible but must be stand-alone action: File as acción de daños under Art.101 TFEU + Art.74 Ley 15/2007, not as cláusula abusiva under LGDCU.

You need independent econometric expert proving 12-month Euribor inflated by X bps during your specific payment dates. Commission decisions alone insufficient.

Quantum minimal: Even Barcelona Court 3 that upheld claims awarded minimal amounts - often €300-€800 for typical €150k mortgage, because 7.05 bps over few years = small.

Prescription: 5 years from when you could reasonably know - generally from publication of Commission decision 2013/2016, but Volvo ruling extends.

No automatic right to suspend foreclosure: Order 33/2015 Madrid says you must prove harm in execution opposition, cannot suspend just by invoking cartel.

In practice, Spanish Supreme Court has not yet ruled on Euribor cartel damages, unlike Trucks cartel where STS 5861/2025, 18 Dec 2025 confirmed overcharge >10% and reinforced effective compensation. Until STS rules on Euribor, lower courts will continue dismissing for lack of proof of causation.