S&P 500 - 1989

The following graph plots the year-to-date performance of the index for 1989 compared to the probability calculated by a random walk model.

Initial Value: 277.72 Hist. Volatility: 0.86% Annual Drift: 7% Final Value: 353.4 Percentile: 89%
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 1989 (what's this?).