Historical market data useful, to a point.(BUSINESS WEEKLY)(Streetwise)(Column)

Byline: Lauren Rudd

Wall Street can be ornery and cantankerous.

For proof, you only have to look at a chart of the major stock indexes over the past 40 years. What you will see is that the indexes fluctuate over time and that at times those fluctuations can become dramatic.

Yet the graph will also show that the major indexes have an undeniable upward trend.

On a more micro level, a graph of the day-to-day stock prices for an individual company will also fluctuate over time, and yet for a quality company the trend is also likely to be upward.

So can you use historical data to predict the future? The answer is unequivocally no. …