NYSE Composite Index - 2009

The following graph plots the year-to-date performance of the index for 2009 compared to the probability calculated by a random walk model.

Initial Value: 5757.05 Hist. Volatility: 2.15% Annual Drift: 7% Final Value: 7184.96 Percentile: 72%
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 2009 (what's this?).