Brownian Motion (GBM)
Project probabilistic price paths forward.
Geometric Brownian Motion is the model behind much of quantitative finance. The overlay projects a fan of possible future paths from the current price, given its recent drift and volatility.
How to read it
- The fan shows a cone of outcomes — not a prediction, but a range of where price could plausibly be.
- The cone widens with time: the further out, the more uncertain.
- Recent volatility sets how wide the cone opens; recent drift tilts it.
Honest framing: GBM assumes random, log-normal moves. Real markets have fat tails and trends it doesn’t fully capture. Use it for context and risk framing, not as a forecast.