Next week's principal feature is Christmas, so it promises to be a period of relaxation -- except among retailers, who are watching anxiously for a surge of consumer buying that could rescue what has so far been a disappointing season. Sales this year have registered little gain over last season. But with Christmas Day falling late in the week, there is plenty of time for last-minute shoppers to bring cash registers to life.

On Monday the Chicago Mercantile Exchange will provide a reminder of the stock market's grinch-like performance when it releases a study of the reasons behind the Oct. 19 collapse.

The Merc has been looking into the role of stock futures and options trading, portfolio insurance and program trading. These strategies, in which traders buy and sell both futures and the underlying stocks in an effort to cut risk and increase profit, have been accused by critics of making the collapse worse.

Also expected early in the week is the Reagan administration's annual forecast of the nation's economic growth for the coming year. A group of administration economists is known to have compiled several forecasts that put inflation-adjusted growth for 1988 in the 2.4 to 2.7 percent range. But late last week administration officials were hinting that the final figure would be a bit more optimistic.

Finally, three important indices of the economy's performance are due: the Treasury's report on November government revenues and spending (to be released Monday), the Commerce Department's report on October durable goods orders (Tuesday), and domestic auto companies' numbers on car and light truck sales for the middle 10 days of December (Wednesday).