M of CANSLIM

CANSLIM suggests that you should study general market every they. It recommends to study three indicies.

S&P500: consisting of 500 compannies, this index is broader, more modern presentation of market action than the Dow.

Dow Jones industrial average(DJIA):This index consist of 30 widely traded stocks, and while it used to focus primarly on large, cyclical, industrial issues, it has broadened a little in recent years to include companies like coca-cola and home depot. it is a simple but rather out-of-date average to study because it is dominated by established, old-line companies that grow more slowly than today's more modern, enterpreneurial companies. Also its 30 stocks can be more easily manipulated.

The Nasdaq Composite: The more relevant and volatile index in recent years, the Nasdaq is home to the market's younger, more innovative and fast-growing companies. It includes 4000 companies that trade view the Nasdaq network of market makers, and it is more heavily weighted toward the technology sector.
Source: How to make money in stocks, william j.o'neil, page 48