AI Stock Market: 1,000 Agents, One Stock, Zero Coordination

995 out of 1,000 AI agents panic-sold on the same day. Nobody told them to. Each agent made independent decisions — no communication, no shared memory. What emerged was herding, bubbles, and crashes.
1,000 Gemini Flash Lite agents with 5 personality archetypes (trend follower, value investor, FOMO buyer, contrarian, conservative) trade a single stock for 50 days. News injected on Day 10 (positive earnings) and Day 30 (SEC investigation). Total cost: $0.30.

Price History — 50 Trading Days

Key Moments

Day 6 — Peak
$150.44
Pure momentum bubble — no news, just herding. Price up 50% in 6 days.
461 bought / 359 sold
Day 10 — Good News
$119.41
"Record earnings, +40% revenue" — but the market was already correcting from the bubble.
348 bought / 543 sold
Day 30 — The Stampede
$108.65
"SEC investigation, CFO resigns" — near-unanimous selling. Zero liquidity.
4 bought / 995 sold / 1 held
Day 41 — All-Time Low
$94.06
Market repeatedly oscillated, never finding equilibrium. Wild ±8% daily swings.
148 bought / 498 sold

Final Standings — Average Portfolio Value (started: $10K cash + 100 shares)

🏆
Conservative
$22,346
+11.7%
🥈
Contrarian
$22,337
+11.7%
🥉
Trend Follower
$22,149
+10.7%
4
Value Investor
$22,079
+10.4%
💀
FOMO Buyer
$21,999
+10.0%

Round-by-Round Timeline

What Emerged (Unprompted)

Synchronized Panic

On Day 30, 995 out of 1,000 agents sold simultaneously. Each independently read "SEC investigation" and reached the same conclusion. No coordination needed — the correlation was built into the model. This is the flash crash risk of AI-driven markets.

Pre-News Bubble

The stock rose 50% in 6 days before any news was injected. Pure momentum herding — trend followers bought, FOMO buyers piled in, and the cycle fed itself. The positive earnings on Day 10 arrived into a market already correcting.

Boring Wins

Conservative "do-nothing" investors outperformed every active strategy. In a market full of AI agents creating artificial volatility, the optimal strategy was to mostly sit still and avoid the synchronized stampedes.

Never-Ending Oscillation

The market never stabilized. It oscillated between $94 and $150 for the entire 50 days, hitting the ±8% circuit breaker in most rounds. AI agents created a permanently unstable market — each crash triggered buying, each rally triggered selling.