NEW YORK -- Many of the nation's charitable foundations were bruised by the stock market's plunge on Oct. 19, but none -- including the giant Ford Foundation, which took a $358 million hit -- anticipates short-term cutbacks in gifts.

The optimistic outlook, expressed in interviews last week, is due in most cases to the diversification of investments and the making of astute post-collapse moves. As a result, foundations appear to be gaining back some of the losses.

That is good news for social programs, people applying for grants to support research, and other charitable works domestically and abroad.

By law, the philanthropic foundations must give away at least 5 percent of their assets for charitable purposes each year. The gift programs typically are figured on a three-year basis. That is considered short-term.

The future, or long-term, giving will hinge on stock market behavior in the months ahead. If there is a sustained downward course, a shrinkage in gifts is likely.

Several days after the collapse, the Ford Foundation, with current gifts totaling $200 million a year, made stock market moves that gained back half the losses, according to John W. English, vice president and chief investment official.

The Ford losses Oct. 19, though dizzying at $358 million, could have been much more severe. "We are permitted to have 40 percent to 80 percent of our holdings in equity investments {stocks}," said English. "In February we took $1 billion in equities out of the market, reducing our equity exposure to a low point. So when the storm hit we were at 41 percent. The steps we had taken to reduce our equity exposure helped. We still lost but we would have lost more."

As of last week, assets of the Ford Foundation were at $4.6 billion.

The Ford Foundation is somewhat typical of other foundations, a check showed. Many reduced stock holdings in the weeks or months before the fall in the belief that the bull market was due for a plunge.

At the Edna McConnell Clark Foundation, named for the daughter of the founder of Avon Corp., officials last February reduced its market holdings by $14 million to guard against catastrophic losses. Despite that move, the foundation lost 10 percent to 11 percent of its assets since Sept. 30, sliding from $335.5 million from $381 million.

At the Rockefeller Foundation, the nation's 10th largest, assets were $1.86 billion on Sept. 30, said Susan L. Russell, a communications officer. As of the close last Friday, its assets totaled $1.6 billion. "On Black Monday we were at $1.5 billion -- down 17 percent from the close Sept. 30," she said.

It could have been a lot worse at the Rockefeller Foundation, too. Russell noted that on Dec. 31 last year, 61 percent of assets were in stocks. On Oct. 19, the foundation had just 46 percent in stocks.

"We have since bought some stock," Russell said last week. "As of Wednesday of this week, we had 53 percent in stocks," adding, "We don't anticipate any changes in our giving plans -- at least through 1988."