Stock index futures trading will be reported in The Washington Post's daily and Sunday commodity tables starting today.

The new listings include the Kansas City Board of Trade's Value Line futures contract, the Chicago Mercantile Exchange's Standard & Poor's 500 Stock Index futures contract and the New York Stock Exchange Composite Index futures contract traded on the New York Futures Exchange.

Stock index futures are similar to wheat, corn or other commodity futures contracts except that the "commodity" involved is a hypothetical portfolio of stocks. Each stock portfolio is represented by one of the widely quoted stock market indices.

Speculators who expect the New York Stock Exchange Index to rise can try to make money by buying NYSE Index Futures. If the index does go up, the futures contract will increase in value and can be sold at a profit. Speculators expecting a decline can sell stock index futures and profit from the drop in prices.

Unlike other futures contracts, stock index futures transactions are settled in cash. A buyer of stock index futures is not entitled to take delivery of the portfolio of stocks represented.

Because of the difficulty of predicting the overall trend of markets and the potential for large losses if the markets move in the wrong direction, stock index futures are considered a high risk speculation and not suitable for some investors.

A federal court in New York yesterday refused to allow the Commodity Exchange Inc. to trade a futures contract based on a copy of the Standard & Poor's Index. Dow Jones & Co. has also filed suit to prevent the Chicago Board of Trade from offering a contract based on the Dow Jones Industrial Average.