In 1982 the Chicago Mercantile Exchange brought out the S&P 500 and the life of an index trader was possible. You could buy or sell the equivalent of the 500 largest capitalization stocks in the country, stocks on the New York Stock Exchange, on the American Stock Exchange, on the Nasdaq stock exchange all in one index of 500 different issues. This index was composed of big corporations, utilities, and transportation companies. A smorgasbord of capitalism in its finest state.

Later the Nasdaq 100, an index of the 100 largest companies in the Nasdaq composite was created and offered by the CME. As well as the Mid-Cap 400 and others including the Russell 2000. No need to study company's balance sheets and financial statements to determine which one to invest in.

You need to study the charts for clues that would enable you to take a position long or short in the index of your choice and at the proper time, sometime later, neutralize that position with a profit for your efforts.

You know before hand what the cost of data feed and charting software will be on a monthly basis.

Your capital requirements and commissions per contract, per round turn. Overnight exposure can affect your ability to sleep as news events can cause dramatic moves in the market overnight. You never know what you are going to wake up to.

Daytrading may be accomplished with a smaller account than that which is required for overnight exposure. And at the end of the trading day, you have NO open positions to worry about, thus eliminating the overnight exposure.