The day Wall Street trembled – Black Monday, October 19, 1987
On the morning of October 19, 1987, nothing hinted at the impending disaster.
But by the market close, US stock indices had already recorded their sharpest daily decline in history.
- The S&P 500 index crashed by 20.5%
- The Dow Jones index collapsed by 22.6%
All of this in just one day.
The world watched in complete shock.
Stock exchange traders watched screens turn red, and panic spread at lightning speed across the globe.
Computers, which until then were considered 'innovative' in algorithmic trading management, actually accelerated the collapse – automatic sell orders created a deadly chain reaction.
But what did we learn from Black Monday?
Unsupervised technology can increase risk – even in the stock market, automation requires a balance between efficiency and control.
Market psychology is stronger than anything – fear spreads faster than any chart or economic analysis.
Need for systemic circuit breakers – following this day, Circuit Breakers were born, automatic switches that halt trading during sharp declines to prevent mass panic.
History repeats itself – but markets mature – since then, markets have experienced many crises, but each one built a new layer of resilience for the system.
Black Monday reminds us that economics is not just numbers – it is also emotion, trust, and fear.
And the most important lesson?
Stability is not self-evident. It is rebuilt every day the market opens.