The Swiss Franc Shock: A Currency Peg That Broke Without Warning
The Swiss National Bank abruptly abandoned its franc-to-euro cap, sending the currency up as much as 30% in minutes and instantly wiping out — or reversing into deep negative balances — countless leveraged retail forex positions.
- EUR/CHF move
- Roughly 30% in minutes
- Warning given
- None
- Broker impact
- Several forced into insolvency or large losses
What happened
Since 2011, the Swiss National Bank (SNB) had maintained a floor under the EUR/CHF exchange rate, committing to buy unlimited euros to prevent the Swiss franc from strengthening past a set level. Years of consistent defense of that floor led much of the market to treat it as a near-permanent fact, and many traders held leveraged positions built on the assumption it would hold.
On January 15, 2015, with no advance warning, the SNB abandoned the cap entirely. The franc surged against the euro by as much as 30% within minutes — a move that, for most currency pairs, would be considered enormous over the course of an entire year, not a few minutes.
For leveraged forex accounts positioned on the assumption the peg would hold, the losses were often larger than the capital in the account. Several retail brokers found their clients owing them more money than the clients had deposited, and at least one major broker (Alpari UK) was forced into insolvency as a direct result, while others required emergency capital.
Why it still matters
This event is the modern, near-exact echo of Black Wednesday decades earlier: a currency peg held for years, treated by the market as effectively permanent, and then removed without warning — because central banks are not obligated to give the market advance notice of a policy change.
For anyone trading currency pairs with leverage, it is the clearest possible argument for always having a real stop in place, even on positions that seem structurally safe. A pegged or tightly managed currency can still gap violently — the peg does not remove the risk, it just compresses years of potential movement into a single moment when it eventually breaks.