Early gains evaporated after the Fed reported a sharp increase in a measure of the money supply.

A small increase is expected, but not so large as the gains reported for May and June.

Spending on personal consumption, which accounts for nearly two-thirds of economic activity, is now shown to have climbed at a 2.2 percent rate during the spring, twice the gain reported earlier.

The revision showed September orders even weaker than the gain of one-tenth of 1 percent initially reported.

More signs of economic strength appeared today, as a major forecasting index showed its third straight gain and the Government reported a sizable, broad-based rise in new construction.

Also, the gains reported for the selected chemicals did not include those expected from proposed improvements that did not have budget approval by April 30.

But they attributed I.B.M.'s strong gain to general market conditions as well as the higher earnings reported yesterday by two other computer makers.

Whether or not the seller elects out, the total net gain or loss reported will be the same, but timing and characterization can vary widely.

The latest employment report also lowered the strong gains reported earlier for January and February.

Only about 8 percent of all individual taxpayers reported any capital gains in 1994, the most recent year for which the Internal Revenue Service has estimates.