What Happened When Switzerland Abandoned Its Franc Peg in 2015?

On January 15, 2015, in a decision that shocked global financial markets, the Swiss National Bank (SNB) announced that it would abandon its minimum exchange rate of 1.20 CHF per euro (a floor it had defended for three and a half years), allow the franc to appreciate freely, and shift toward negative interest rates. Within minutes, the Swiss franc surged 30% against the euro, the largest single-day appreciation in decades. Forex traders who had bet that the floor would hold lost billions. Currency options markets imploded as thousands of retail forex traders and hedge funds faced margin calls. Forex brokers discovered that their algorithms had failed, and over-the-counter markets experienced a day of chaos and uncertainty. Unlike the crises of the 1990s and early 2000s, which involved collapsing emerging-market currencies and contagion, Switzerland's shock was a developed-market currency appreciation—yet it still produced significant financial damage. This article examines why the SNB abandoned the peg, the mechanisms through which the shock propagated, and the implications for currency markets and central bank credibility.

Quick definition: The 2015 Swiss franc shock occurred when the SNB unexpectedly announced it would abandon its 1.20 CHF/EUR floor, allowing the franc to appreciate 30% in minutes and triggering massive losses for forex traders who had bet on the peg's persistence.

Key takeaways

• The SNB had established a minimum exchange rate of 1.20 CHF/EUR in September 2011 to prevent the franc from appreciating (which would hurt Swiss exports and potentially deflate the economy)
• The floor required the SNB to intervene massively in the currency market (purchasing euros and other foreign assets) to prevent the franc from strengthening below 1.20
• By 2014, the SNB's balance sheet had grown to 85% of Swiss GDP, the largest balance sheet relative to GDP among major central banks, due to continuous forex interventions
• Quantitative easing (QE) by the European Central Bank created downward pressure on the euro, making the floor increasingly difficult and expensive to defend
• The SNB realized that defending the floor against QE indefinitely would require unlimited balance-sheet expansion, creating risks of massive losses if the euro subsequently weakened
• The decision to abandon the floor was economically rational but had not been signaled in advance, producing a classic "surprise shock" in financial markets
• The shock devastated currency speculators who had accumulated massive long positions in the euro (betting on a weaker franc)

The Origins of the Peg: The Safe-Haven Crisis

The Swiss franc has long been considered a "safe haven" currency—a currency that investors buy when they are frightened by global risk. During the financial crisis of 2008–2009 and the European sovereign debt crisis of 2010–2011, capital flowed into Switzerland in massive quantities, seeking safety. This capital inflow appreciated the franc, making Swiss goods more expensive and threatening the competitiveness of Swiss exporters.

From 2008 to 2011, the franc appreciated from 1.62 per euro to 1.20 per euro, a 26% real appreciation. This appreciation threatened deflation in Switzerland (as import prices fell) and recession (as export demand declined). The SNB, concerned about the risks, established a minimum exchange rate of 1.20 CHF per euro in September 2011, committing to intervene massively to prevent further franc appreciation.

The floor mechanism was simple: if the market exchange rate moved toward 1.20 (the franc strengthening more), the SNB would automatically buy euros, driving the rate back down toward 1.20. The SNB promised "unlimited" support for this floor, signaling to speculators that betting on franc appreciation was futile.

The strategy worked for three and a half years. The floor was successfully defended, and the franc remained stable at 1.20 per euro despite the continued safe-haven demand for Swiss assets. Speculators who had bet on franc appreciation initially suffered losses as the floor held. By 2014–2015, many speculators had given up on franc appreciation and had repositioned to bet that the floor would hold indefinitely, accumulating massive euro-long positions (betting that euros would not depreciate below 1.20 per franc).

The QE Dilemma: Defending Against Monetary Expansion

In January 2015, the European Central Bank announced a massive quantitative easing program (QE), planning to purchase 60 billion euros per month of government and corporate bonds. The ECB's QE was designed to lower eurozone interest rates and depreciate the euro, stimulating growth in the slow-growing eurozone economy.

For the SNB, the ECB's QE created an impossible situation:

The capital inflow pressure: QE in the eurozone increased the demand for non-euro assets (as investors sought higher returns elsewhere or reallocated portfolios away from the newly-supplied euros). Capital flowed out of euros into Swiss francs, creating downward pressure on the euro (upward pressure on the franc) that the SNB would need to resist.

The balance-sheet expansion: To defend the 1.20 floor against ECB QE, the SNB would have needed to purchase unlimited quantities of euros (and other foreign assets). The SNB's balance sheet had already grown to approximately 450 billion francs (85% of Swiss GDP), the largest balance sheet among major central banks relative to GDP. Further expansion would create several risks:

1. Currency mismatch risk: The SNB was holding euros and other foreign assets, creating losses if those currencies depreciated. If the ECB successfully depreciated the euro further, the SNB's portfolio of euro assets would generate losses.

2. Inflation risk in the balance sheet: If the SNB's massive balance sheet (accumulated through forex interventions) eventually needed to be unwound through sales of foreign assets, this could create currency appreciation pressure and inflation as the foreign assets were converted back to francs.

3. Political risk: The SNB's massive balance sheet meant that the institution held substantial foreign-currency exposure. If foreign assets depreciated, the SNB would record losses, and Swiss taxpayers (who ultimately own the SNB through the government and the Swiss National Bank Act) would bear the loss.

The strategic error: The SNB had implicitly committed to defending the 1.20 floor "forever," but it had not anticipated that a major central bank (the ECB) would pursue policies that made the defense impossible without unlimited balance-sheet expansion.

The Shock: Announcement and Market Reaction

On January 15, 2015, at 10:00 AM CET, the SNB announced that it would abandon the 1.20 minimum exchange rate floor and allow the franc to float freely. The decision was communicated through a press release, with the SNB Governor available for questions immediately afterward. There had been no advance warning; the decision was a complete surprise to financial markets.

Within seconds of the announcement, the currency market seized up. The EUR/CHF exchange rate, which had been trading around 1.200 (supported by the floor), moved rapidly toward 1.0. The last few transactions occurred at 1.15 CHF per euro, but as the volume of buy orders for francs overwhelmed sell orders, the market became dysfunctional.

Within five minutes, the franc had appreciated approximately 15% (from 1.200 to 1.025). Within an hour, it had appreciated 30% (trading near 0.850 CHF per euro). The one-day move was the largest single-day appreciation of the franc in over a decade.

The shock produced several direct effects:

Forex trader losses: Traders who had accumulated massive long positions in the euro (betting that the floor would hold) suddenly faced 30% losses on their positions. A trader with a 1-billion-euro position with 10:1 leverage faced a loss of 3 billion francs (approximately $3.2 billion). Hedge funds and proprietary trading desks at banks suffered unexpected losses.

Broker failures: A number of retail forex brokers, which had offered leverage to retail traders (100:1 or higher leverage), experienced losses that exceeded their capital. Many brokers had assumed they were fully hedged (protected against currency movements) but discovered that their hedging was inadequate. FXCM, a major US forex broker, faced losses of approximately $225 million and was eventually sold to Gain Capital.

Options market implosion: Currency options (contracts giving the right, but not obligation, to exchange currencies at a specified rate) that had been sold short by speculators suddenly moved deeply out of the money. The value of those options exploded, and traders who had sold the options faced enormous losses. Pricing models broke down as the 30% move in an hour exceeded typical 10-year volatility expectations.

Liquidity evaporation: Bank dealers that typically provide liquidity in currency markets suddenly stopped quoting prices. The bid-ask spreads (the difference between the price at which you can buy and the price at which you can sell) widened from typical 1–2 pips (0.01–0.02 centimes) to 50–100+ pips. This made it impossible for traders to exit positions at reasonable prices.

The Mechanisms of Market Dysfunction

The 2015 franc shock revealed several vulnerabilities in global currency markets:

Model failure: Risk models used by banks and trading firms had been calibrated using historical volatility data. The largest single-day franc move in decades exceeded the worst-case scenarios in these models. Value-at-Risk (VaR) models that had estimated maximum daily losses at $50 million suddenly faced actual losses of $200+ million. This mismatch forced many institutions to liquidate other positions to meet margin requirements.

Leverage implosion: The forex market is heavily leveraged. Retail traders can trade with 100:1 leverage, meaning a 1% move produces a 100% loss on capital. When the franc appreciated 30% in an hour, a trader with $10,000 and 100:1 leverage in a long-euro position faced a loss of 300 times the initial capital ($3 million). Margin calls were made, and brokers were forced to liquidate positions immediately.

Algorithmic trading failure: Many banks use algorithms (automated trading programs) to manage risk and provide liquidity. These algorithms are designed to automatically reduce exposure when volatility spikes. On January 15, when the franc shock hit, algorithms across the market all tried to reduce euro exposure simultaneously, selling euros to buy francs. This feedback loop accelerated the franc appreciation and prevented the market from finding an equilibrium price.

Counterparty risk: Forex dealers trade with each other on an over-the-counter (OTC) basis, with credit between counterparties. When large losses appeared, there was suddenly uncertainty about which institutions would fail. This counterparty risk concern caused some dealers to stop quoting prices to other dealers, effectively shutting down the market for a few hours.

Why Did the SNB Abandon the Floor?

The SNB's decision to abandon the floor, while shocking to markets, was economically rational:

Balance-sheet risk: The SNB's balance sheet had grown to 450 billion francs (85% of Swiss GDP), making it by far the largest central bank balance sheet relative to GDP. This concentration of currency exposure created risks that the SNB was not comfortable with indefinitely. If the SNB had continued defending the floor against ECB QE, the balance sheet would have grown to perhaps 600+ billion francs (130% of Swiss GDP), an unprecedented level.

Exit risk: Defending the floor forever was never sustainable. At some point, the SNB would want to exit the floor and normalize monetary policy. However, the longer the SNB waited, the larger the imbalance and the more painful the eventual exit would be. By exiting in January 2015, the SNB chose to take the pain immediately rather than delay it.

Forward guidance failure: The SNB had repeatedly stated that it would defend the floor "as long as necessary," but the ECB's QE changed the calculus. The SNB chose not to explicitly revise its forward guidance before the announcement, apparently believing that the decision needed to be a surprise to prevent markets from gradually repricing in advance (which would have allowed some traders to exit long-euro positions before the shock).

Interest rate flexibility: By abandoning the floor, the SNB regained the flexibility to implement negative interest rates more aggressively. The SNB subsequently implemented -0.75% interest rates on bank reserves, a step that would have been undermined by continued currency-floor defense.

Real-world examples

FXCM's crisis: FXCM, a major US retail forex broker, faced losses of $225 million from the franc shock. The firm had assumed that currency volatility would remain within historical ranges and did not have sufficient capital to withstand a 30% move. The firm sold a majority stake to Gain Capital and had to restructure its business substantially.

A currency trader's 30% loss: A retail trader with $100,000 in an account and 10:1 leverage accumulated a long-euro position (betting that euros would strengthen). With $1 million in notional exposure, a 30% appreciation of the franc meant a loss of $300,000—three times the initial capital. The trader's account was liquidated, and the trader owed the broker $200,000.

Bank losses: JPMorgan Chase reported losses from the franc shock. The bank had outstanding forex positions that, while hedged, still produced losses due to the magnitude of the move and basis risk (the hedges were not perfectly matched to the underlying exposure). The bank reported losses of approximately $50 million, a relatively small amount for the institution but significant enough to merit disclosure.

The options-seller's catastrophe: An options trader who had sold 1-month franc call options (contracts allowing the buyer to purchase francs) at a strike price of 1.10 CHF/EUR had collected a premium of 0.5 CHF cents per euro. This 0.5-cent premium was the maximum profit. When the franc appreciated to 0.85 CHF/EUR, the options moved 25 cents into the money, and the trader faced losses of 4,900% of the initial premium collected.

Common mistakes

1. Assuming central banks always provide advance warning: Many investors and traders believed the SNB would provide some indication before abandoning the floor. This assumption proved wrong. Central banks sometimes change policy suddenly to prevent speculators from front-running the decision. The SNB chose surprise over transparency.

2. Confusing "unlimited" support with "forever" support: The SNB had promised "unlimited" intervention to defend the floor, but unlimited support for a fixed period is not the same as permanent support. Once ECB QE made the defense unsustainable, the SNB abandoned the commitment.

3. Overexposure to single trades: Many traders had accumulated massive long-euro positions betting on franc weakness. Concentration in a single trade is extremely risky; a surprise policy change can eliminate years of profits. Better practice would have been to hedge the position with franc call options (which are expensive but provide protection against surprise appreciation).

4. Underestimating tail risk: VaR and risk models are calibrated using recent history. The 30% one-day franc move was outside historical experience, so it did not show up in standard risk models. A more conservative approach would have included stress scenarios (days like January 15, 2015) in the risk framework.

5. Leverage overuse: The traders and brokers that were destroyed on January 15 had used extreme leverage (100:1 for retail traders, 20–30:1 for professional traders). High leverage amplifies both profits and losses; a 30% move produces 300% losses at 10:1 leverage. Prudent risk management would have limited leverage to levels that could survive a 5–10% daily move.

FAQ

Why did the SNB care about franc appreciation if Switzerland is a wealthy country?

Franc appreciation reduces Swiss export competitiveness and can potentially cause deflation (falling prices), which discourages economic activity. Although Switzerland is wealthy, it is also a small, open economy dependent on exports (precision manufacturing, pharmaceuticals, financial services). Franc appreciation can seriously hurt these export sectors. Additionally, the SNB worried that if the franc appreciated sharply, it might trigger a deflationary spiral that would be difficult to reverse.

Could the SNB have abandoned the floor more gradually?

In theory, yes. Instead of a surprise announcement, the SNB could have announced that it would gradually raise the EUR/CHF floor from 1.20 to 1.15 to 1.10, signaling its intention to allow gradual appreciation. This would have allowed traders time to adjust positions. However, gradual adjustment would have given speculators time to front-run the process (accumulating franc positions ahead of the announced appreciation), undermining the SNB's ability to exit the floor cleanly.

Why was the franc so strong that it needed a floor?

The franc is strong because of Switzerland's reputation for political stability, strong institutions, and a sound monetary policy history. During global crises (2008–2009, 2010–2011, post-2020), capital flowed into Switzerland seeking safety. This safe-haven demand appreciated the franc. A floor (which required the SNB to buy foreign currency) was designed to prevent excessive appreciation that would harm export competitiveness.

Did the franc subsequently weaken?

No. After the initial 30% appreciation on January 15, the franc stabilized at a higher level (around 0.95 CHF per euro) and has remained strong since. The SNB's abandonment of the floor revealed that the franc's underlying strength was not due to the floor; the floor had simply been restraining the franc's natural appreciation tendency. Once released, the franc strengthened toward its equilibrium level.

How did the broader financial markets react?

The shock was largely contained to the forex market and institutions with massive currency exposures. Stock markets fell 2–3% on the day but recovered within days. Credit markets experienced a brief widening of spreads but stabilized quickly. The ECB and other central banks did not view the franc shock as a systemic risk to the financial system. This contained impact distinguished it from the 1990s–2000s currency crises, which had spread contagion across asset classes.

Did this shock change central bank communication?

Somewhat. Central banks became more aware of the risks of unexpected policy changes in highly leveraged markets. However, they also became more willing to act with surprise when they believed that gradual communication would allow speculators to game the system. The SNB's actions demonstrated that central banks would prioritize policy effectiveness over market transparency when the two come into conflict.

How many forex traders failed after the shock?

Exact figures are difficult to obtain, but several prominent forex brokers failed or were acquired: FXCM was sold to Gain Capital, Alpari failed, and several other smaller brokers closed. Estimates suggest that the combined losses across the industry exceeded $1 billion. Most losses fell on professional traders and institutions rather than retail traders, since retail traders were often protected by negative-balance protection rules that prevented losses exceeding account deposits.

Related concepts

• What Is a Currency Crisis?
• Anatomy of a Currency Crisis
• The Thai Baht Collapse
• The Turkish Lira Crisis

Summary

The 2015 Swiss franc shock was a different kind of currency crisis—not an emerging-market collapse driven by twin deficits and capital flight, but a developed-market appreciation driven by central bank policy surprise. The SNB's decision to abandon a 1.20 CHF/EUR floor that it had defended for three and a half years caught the market off-guard, triggering a 30% franc appreciation in minutes. The shock demonstrated that even in transparent, developed financial markets, extreme leverage and concentrated positions can be destroyed by policy surprises. Traders and brokers who had accumulated massive bets on franc weakness faced catastrophic losses. Options markets experienced dysfunction as pricing models broke down. The shock also revealed the unsustainability of the floor: the SNB's balance sheet had grown to 85% of Swiss GDP in defending it, and ECB QE made continued defense impossible without unlimited balance-sheet expansion. Unlike the crises of the 1990s and early 2000s, the 2015 franc shock produced limited systemic contagion, but it demonstrated that leverage, concentration, and surprise policy changes remain potent combinations in global currency markets. The episode highlighted the importance of tail-risk hedging and limits on leverage, lessons that were reinforced a decade later by other financial market shocks.

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