S&P 500 - 1956

The following graph plots the year-to-date performance of the index for 1956 compared to the probability calculated by a random walk model.

Initial Value: 45.48 Hist. Volatility: 0.74% Annual Drift: 7% Final Value: 46.67 Percentile: 40%
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 1956 (what's this?).