Crash · S&P 500 Index (1987)
Replay 144 daily bars of the 1987 S&P 500 crash, where the index fell 16.5% and saw a 20.5% single-bar plunge. Walk through each trading day, face 9 pivotal decision points, and receive an AI coach review of your simulated capital choices.
144 daily bars · 25 decision points · 1987-06 to 1987-12 · Stocks
Key facts
This window spans 205 days with a peak-to-trough drawdown of 33.5% and a 14.9% run-up.
- Max drawdown
- −33.5%
- Max run-up
- +14.9%
- Duration
- 205 days
- Largest single-day move
- −20.5%
- Bars
- 144 Daily bars
- Decision points
- 25
Every figure above is computed programmatically from this replay’s own candle series — no editorial input, no LLM. Methodology: Methodology
The market advances day by day. You only see candles up to the current day — as if you were really there.
At key decision points choose Buy / Trim / Exit / Hold. Each decision advances the timeline by one day.
After settlement you get a six-dimension score and an AI coach review. Your result enters the scenario leaderboard.
Event Replay
What happened — and what it teaches
Between June and December 1987, the U.S. equity market entered one of its most studied stress episodes, with the S&P 500 Index sliding from 296.72 to 247.86 over 144 daily bars. The setup combined elevated valuations, fresh monetary tightening, and growing unease about global imbalances, putting late-cycle capital allocation, hedging, and leverage decisions under an unusually bright spotlight. Stakes for any participant were not merely directional: with volatility quietly expanding, every trade had to clear a higher bar for risk-adjusted reasoning.
What unfolded was a fast and violent repricing. The index closed the period down 16.5%, but the headline number conceals the path: a peak-to-trough drawdown of 33.5%, punctuated by a 20.5% single-bar plunge that crystallized the panic. Twenty-five decision points, nine of them critical, forced trainees to confront stop placement, sizing, and conviction maintenance while intraday ranges exploded. The data ask one core question: how do you act when the historical record you trusted has just been invalidated by a single session?
For decision training, the 1987 arc is less about predicting the crash and more about rehearsing response. The exercise trains process discipline: pre-commitment to position sizes, scenario-based exit rules, and the willingness to cut exposure before narrative fully explains the move. It also surfaces psychology lessons — the cost of anchoring to prior calm regimes, the danger of adding into falling markets, and the value of defining “I was wrong” criteria in advance. Replayed with simulated capital, the period becomes a laboratory for testing whether your framework degrades gracefully when the largest single-bar move is not a tail event but a present-tense fact.
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