What Is Black Swan?
A black swan is an unpredictable, extreme event with massive market impact. Coined by Nassim Nicholas Taleb, black swans are characterized by: rarity (they lie outside normal expectations), severe impact (they reshape markets), and retrospective explainability (after the fact, people rationalize why it was "obvious"). In crypto, examples include the March 2020 COVID crash, the Terra/LUNA collapse, and the FTX implosion.
How Black Swan Works
Black swans cannot be predicted by standard risk models because they fall outside the distribution those models assume. A strategy backtested over 5 years of "normal" conditions will not account for a 60% single-day crash. Position sizing, leverage limits, and hedging strategies must account for events that have never happened before but could.
Why It Matters for Traders
Surviving black swans is more important than optimizing for normal markets. Strategies that blow up during black swans don't matter how profitable they are in between. The practical defense: never use more leverage than you can survive a 50%+ adverse move, maintain emergency cash reserves, use options for tail risk protection, and diversify across uncorrelated strategies and custodians.
