Both simulations here use generated, not real, data — a random-walk price feed for the Market Maker game, and illustrative long-run return/volatility assumptions for the Portfolio Risk Simulator (not live prices, not any specific published forecast). What's real is the mechanics: spread capture vs. fill rate, inventory risk, mark-to-market P&L, risk limits, and a genuine Monte Carlo/VaR calculation running entirely in your browser.

Simulations

Sit in the seat

Every other module on this site is about analyzing markets from the outside. These two are about the actual job: running a trading book like a sales & trading desk, and building and stress-testing a portfolio like a risk or asset-management analyst.

Market Maker — a sales & trading desk

Quote a bid/ask spread around a moving price and see what actually happens to your P&L as customer flow trades against you.

You quote a bid and ask around a moving mid price for 90 ticks. A tighter spread gets hit more often but earns less per trade; a wider spread earns more per trade but gets hit less. Breach the ±40-share risk limit and the desk will forcibly hedge you at a penalty price.

Portfolio Risk Simulator — asset management & risk

Build a portfolio across 10 asset classes and run a real 500-path Monte Carlo simulation to see the full distribution of 1-year outcomes — not just an expected return, but the shape of the risk around it.

Starting portfolio: $100,000. Set weights below (they'll be normalized to 100% automatically), then run 500 simulated 1-year paths.

US Large-Cap Equities

Equities · exp. return 10.0% · vol 16%

50

US Small-Cap Equities

Equities · exp. return 11.0% · vol 20%

0

Developed Intl. Equities

Equities · exp. return 8.0% · vol 18%

20

Emerging Market Equities

Equities · exp. return 9.0% · vol 22%

0

US Investment-Grade Bonds

Fixed Income · exp. return 4.5% · vol 6%

30

Long-Duration US Treasuries

Fixed Income · exp. return 4.0% · vol 10%

0

Real Estate (REITs)

Real Assets · exp. return 8.0% · vol 19%

0

Gold

Real Assets · exp. return 6.0% · vol 15%

0

Bitcoin / Crypto

Alternatives · exp. return 35.0% · vol 65%

0

Cash / T-Bills

Cash · exp. return 3.0% · vol 1%

0

Total weight: 100