NYSE AMEX Composite Index - 2000

The following graph plots the year-to-date performance of the index for 2000 compared to the probability calculated by a random walk model.

Initial Value: 876.97 Hist. Volatility: 0.61% Annual Drift: 7% Final Value: 897.75 Percentile: 38%
Click on the image for the high resolution version.

The high to date and low to date prices of the stock plotted against a random walk model for 2000 (what's this?).