Can anyone explain to me the SNB-CHF crisis?

What happened exactly in 2015?

Thanks

Hi iNUKE, I think you could find these articles useful:
SNB Crisis: Retrospective & Impact | DailyForex CHF Crisis Revisited: How The SNB Reshaped Forex Trading

Good question, not just interesting for love of history. It leads on to very relevant practical questions for traders, such as -
Would I have been short or long EUR/CHF at the time?
Does price trend really “predict” news?
Would knowing the fundamentals at the time have allowed me to profit from this crash?