The Swiss Franc Shock: When the SNB Abandoned Its Euro Floor (2015)

Ten-Thirty in Zürich

At 10:30 Central European Time on Thursday, 15 January 2015, the Swiss National Bank published a three-paragraph statement on its corporate website. The policy the SNB had defended for three and a half years — a floor of 1.20 Swiss francs per euro — was abandoned with immediate effect. The accompanying rate decision pushed the target on sight deposits to minus 0.75 percent, the deepest negative rate of any major central bank at the time.

Traders in London, Zürich and Singapore read the release within seconds of its release. EUR/CHF was quoting at 1.2010 when the wires fired. Inside a minute it had traded at 1.10, 1.00, 0.95 and briefly 0.85 on thin electronic books as stop-loss orders cascaded through a market that had been conditioned by forty-one months of one-way risk. The move represented the largest single-day revaluation of a G10 currency in the era of free-floating exchange rates, dwarfing even the sterling break of 1992.

Swiss equities fell ten percent on the session. Nestlé, Roche, Novartis and Swatch, whose revenue streams run overwhelmingly in foreign currency, absorbed the translation hit in real time. Yet the most arresting losses that morning did not occur on the Zürich exchange. They occurred at retail foreign-exchange brokers, at small mortgage banks in Budapest and Warsaw, and inside the hedging books of Swiss exporters who had assumed — as the SNB had repeatedly invited them to assume — that the floor was a durable feature of the monetary landscape.

The 2011 Context

The floor did not arise from ideology. It arose from panic. Through the summer of 2011 the eurozone sovereign-debt crisis had re-entered an acute phase. Greek spreads were widening, Italian and Spanish yields had crossed into unsustainable territory, and a rapidly shrinking pool of perceived safe havens was absorbing the flight. The Swiss franc, together with the Japanese yen, was an obvious destination. Between the start of 2010 and August 2011 the franc appreciated roughly thirty percent on a trade-weighted basis. EUR/CHF, which had traded near 1.55 a year earlier, pierced parity on 9 August, touching 1.0075 intraday.

For an economy whose export sector equals nearly seventy percent of GDP, that pace of real appreciation was intolerable. Watchmakers, pharmaceutical firms and machinery exporters warned of mass layoffs. Domestic hotel bookings collapsed as German tourists stayed home. Deflation risks, already simmering, deepened. The SNB, under then-chairman Philipp Hildebrand, first tried rate cuts and liquidity expansion. Neither worked. The franc continued to strengthen.

On 6 September 2011 the SNB published a statement that has become a central-bank classic. The Bank set a minimum exchange rate of 1.20 francs per euro and pledged that it would "no longer tolerate a EUR/CHF exchange rate below the minimum rate of CHF 1.20" and would enforce the floor "with the utmost determination" and "prepared to buy foreign currency in unlimited quantities" (SNB, 2011). The use of the word "unlimited" was deliberate. A credible commitment to unlimited intervention was the only way to shift the speculative equilibrium.

The effect was immediate. EUR/CHF jumped nine percent that morning and traded above the floor within hours. For the next three years the market tested the commitment rarely and unsuccessfully. The SNB had manufactured, at least temporarily, the appearance of a hard ceiling on the franc.

Three Years of Defence

Credibility is expensive. Holding the floor required the SNB to buy euros whenever private capital inflows pushed the franc toward 1.20 — which, through much of 2012 and again from mid-2014, was almost continuously. The Bank's foreign reserves, which had stood at roughly 240 billion francs before the floor was introduced, reached 495 billion by late 2014 and were still rising. Reserves as a share of Swiss GDP passed eighty-five percent, a ratio matched by no other major central bank. One academic reconstruction documents that the SNB's defence absorbed roughly 200 billion francs of net intervention in the final six months of the regime alone (Jermann, 2017).

The accumulated reserves were not neutral. Euro assets on the balance sheet meant currency risk on the liability side, and a large portion of the reserves had been invested in euro-denominated government bonds, many at yields that would soon turn negative. Any future appreciation of the franc against the euro would crystallise a capital loss on those holdings. By 2014 the SNB was, in effect, short-volatility on its own currency at a scale that had no precedent in peacetime monetary history.

The political backdrop was hardening alongside the balance sheet. A 2014 popular initiative, the so-called Gold Initiative, proposed to force the SNB to hold twenty percent of its assets in gold and to prohibit future gold sales — constraints that would have made further euro accumulation structurally impossible. Voters rejected the proposal in November 2014, but the campaign clarified that the political tolerance for an ever-expanding balance sheet was finite. A parallel debate in the Swiss parliament questioned whether the unlimited pledge was compatible with the SNB's statutory independence.

Outside Switzerland, the signal from Frankfurt pointed in one direction. Through the autumn of 2014 Mario Draghi had escalated the European Central Bank's language on asset purchases, and by December the market was pricing a large-scale public-sector QE programme for the January 2015 Governing Council meeting. That programme, when announced a week after the SNB abandoned the floor, committed the ECB to buying sixty billion euros of bonds per month. Every additional euro the ECB printed would weaken the single currency against the franc and force the SNB to print more francs in response. The arithmetic was becoming unsustainable.

The Decision

The decision to abandon the floor was made by the SNB's three-person governing board — Thomas Jordan, Jean-Pierre Danthine and Fritz Zurbrügg — on the evening of Wednesday, 14 January. The SNB did not pre-brief the Swiss government, the IMF or foreign central banks. Only the federal finance minister was informed a few hours before the announcement. Christine Lagarde, then IMF Managing Director, said publicly two days later that the non-consultation was "a bit surprising." Jordan defended the secrecy by arguing that any leak would have made the exit impossible — the commitment worked precisely because it was unconditional, and a floor known to be under review was no floor at all.

At the Thursday morning press conference Jordan offered the Bank's rationale in compressed form. "Recently, divergences between the monetary policies of the major currency areas have increased significantly," he said, adding that "the minimum exchange rate was introduced during a period of exceptional overvaluation of the Swiss franc and an extremely high level of uncertainty" and that "enforcing and maintaining the minimum exchange rate for the Swiss franc against the euro is no longer justified" (Jordan, 2015). A later study used options data to show that implied probabilities of a near-term exit had begun drifting upward through December but remained below ten percent as late as the Monday before the announcement (Mirkov and Pozdeev, 2019). The market was not pricing the exit; it was still pricing the floor.

The First Minute

What happened in the first sixty seconds after the statement hit the wires is best understood as a liquidity vacuum rather than a price discovery. Algorithmic market-makers that had been posting two-way quotes around 1.2010 withdrew instantly. Human dealers, confronted with a gap risk they had been assured would not materialise, refused to quote. Stop-loss orders clustered below 1.20 — placed by retail traders, systematic funds and exporter hedges — triggered into a vanishing bid, and each execution printed lower than the last.

The single lowest print, around 0.85, occurred on EBS at roughly 10:32 CET and lasted for fractions of a second. By 10:40 the pair had mean-reverted to the 0.95 to 1.00 range. By the close in New York it was trading near 0.985. The absence of market-maker liquidity in the first minute, rather than the eventual revaluation, was what destroyed broker balance sheets — because retail traders had been permitted leverage of up to 200 or 400 to 1 against EUR/CHF, and the gap through stop-out levels turned client accounts negative faster than any risk system could liquidate them.

Broker Carnage

Retail FX brokers had treated EUR/CHF as a near-riskless carry. Margin requirements at many firms sat between 0.5 and 2 percent, implying leverage up to 200 to 1. When the market gapped through stop-loss orders without printing intermediate prices, brokers could not close client positions at quoted stops. Clients owed the broker the full loss, and the broker owed its prime counterparty the full loss — but client balances, legally capped at zero in most retail jurisdictions, could not cover the deficit.

FXCM's rescue by Leucadia came at punitive terms — an initial 10 percent coupon, warrants and earnings participation — and set the company on a path that ended with regulatory exit from the United States in 2017 on separate grounds. Alpari UK's failure forced the Financial Conduct Authority to process the largest retail-broker insolvency since the regime was established. Interactive Brokers disclosed a 120 million dollar client-debit loss but absorbed it from capital without external support, a reminder that under-capitalised brokers were the exception rather than the rule.

The Eastern European Dimension

The most durable damage of the shock did not fall on dealers in Canary Wharf. It fell on households in Warsaw, Budapest, Bucharest and Zagreb who had, during the 2005 to 2008 credit boom, taken out Swiss-franc-denominated mortgages on the assumption that the franc would remain weak against local currencies. Roughly 550,000 Polish households, 300,000 Hungarian households and smaller but still significant cohorts in Croatia and Romania held CHF mortgages. An overnight twenty percent depreciation of the zloty, forint or kuna against the franc translated directly into a twenty percent increase in the local-currency value of outstanding principal and monthly payment.

Hungary had already begun converting CHF mortgages to forint in late 2014, sparing its borrowers the worst of the shock. Poland had not. The Warsaw stock index fell four percent and the Polish zloty dropped nearly nine percent against the franc in a single session. Political pressure for a legislated forced conversion intensified, and over the following three years Polish authorities alternated between voluntary settlement schemes, a bank levy and Supreme Court rulings that ultimately declared many CHF contracts unenforceable. The European Court of Justice took the same view in a series of rulings from 2019 onward. Franc mortgages remain a live balance-sheet issue for Polish banks a decade after the shock.

Forward Guidance and the Floor

The episode reopened a question that had run through monetary policy since the collapse of the Bretton Woods gold-dollar link in 1971: how credible can a central bank's promise of a fixed external anchor be when the domestic balance-sheet cost runs against it? The sterling exit from the ERM in 1992 had answered the question one way — the Bank of England lost the battle to speculators. The Mexican peso devaluation of December 1994 had answered it another — the defence was abandoned when reserves ran out. The SNB in 2015 answered it a third way: the central bank abandoned the peg while reserves were still plentiful, precisely because the cost of further accumulation exceeded the cost of an orderly revaluation.

Forward guidance in the post-crisis era had leaned heavily on unconditional language. The SNB's "utmost determination" language sat alongside ECB President Draghi's "whatever it takes" and the Federal Reserve's calendar-based commitments on rates. What the franc shock illustrated, which the later discussions of yield-curve control in Japan would echo, is that an unconditional commitment is only as durable as the willingness of the central bank to bear the accumulating cost of honouring it. When that willingness falters, the exit — because it must be unannounced — is necessarily disorderly.

The gap-risk lesson for electronic markets was similar to the one drawn from the 2010 Flash Crash: even the most liquid instruments in the world can become illiquid in the time it takes an algorithmic market-maker to withdraw. Retail leverage rules in the European Union tightened sharply afterward under the ESMA 2018 intervention, which capped major-pair leverage at 30 to 1 and introduced negative-balance protection as a mandatory feature. Offshore leverage remained higher and continues to produce episodic blow-ups.

Afterward

Jordan remained SNB chairman until 2024. The Bank's balance sheet continued to expand after the exit, reaching roughly a trillion francs by 2020, largely because negative rates and sporadic unannounced intervention replaced the explicit floor. The franc drifted back above parity with the euro over the following year and spent most of the 2016 to 2019 period in a 1.05 to 1.20 band — a softer, more forgiving version of the managed regime that the 2011 pledge had tried to enforce by fiat.

The broker failures of January 2015 faded from the financial press within a few weeks. The mortgage litigation in Central Europe is still winding through appellate courts. Somewhere in the SNB's unrealised losses on the 800-billion-franc reserve stack is the long shadow of a three-paragraph statement, released at 10:30 CET on a Thursday morning, that ended the illusion of costless credibility.