It was obvious with foresight. Just look at the chart, this pair hadn't been in an uptrend for months.
Pretty sure you can look at plenty charts (including other pegged currencies) and find these kinds of patterns. Once you look at it ex-post, it's mostly apophenia.
I went from demo to live because of EUR/CHF. This is from memory so feel free to pick it apart but I think 1.5 was the big level at the time. Seeing this work (profiting from SNB intervention) amazed me. To me "intervention trade" meant trading on the side of the intervention. Looking back there was plenty of precedent for the opposite being the case. "The chart" is a great answer. Also famously Soros and GBP. I was fortunately not hurt too badly being wrong on this (small, stops, fair enough execution). Hindsight is 20/20 but I actually traded through the higher level (pretty sure 1.5) and saw that go so... why was I long lower? Live and learn.
based on what I saw in the futures market, a stop loss would have been triggered with some minor slippage assuming you were not trading 1000+ contracts. Has anyone else looked at that aspect? Futures were open and moving (EXTREMELY FAST), but a stop appears would have been triggered if entered.
Depends on what is considered "warning". Swissy was pegged at 1.20 to the Euro. When EUR/CHF traded at/near near the peg, the trade was swap Euro for Swissy... if wrong, you got your money back. If right , well... was it a warning there was no meaningful bounce off the peg rate for the time leading to the day of reckoning? Pegs do not work.
A trend is the simplest and least subjective chart pattern, and they're obvious in real time. Any trader thinking EUR/CHF was not in a downtrend leading into the crash should not be trading.
Again, it's ex-post reasoning. For example, DKK was in a more obvious downtrend - the peg held and it bounced back violently. PS. not trying to belittle you as a trader, rather saying that it's hard to make predictions especially about the future
Its very easy to predict that holding a long position in an enduring and consistent downtrend is a probable poor strategy. No traders should have been long EUR/CHF when the SNB ended its buy EUR policy. The downtrend had become visible months earlier.