US STOCKS-Wall St gains as megacap growth stocks lead

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Tesla to give customers one-month driver-assist trial; shares up

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McCormick jumps after Q1 profit, sales beat

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Trump Media & Technology surges on debut after SPAC merger

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Indexes up: Dow 0.22%, S&P 0.20%, Nasdaq 0.26%

(Updated at 2:05 a.m. ET/ 1805 GMT)

By Chuck Mikolajczak

NEW YORK, March 26 (Reuters) -

U.S. stocks rose modestly on Tuesday after a two-day slide, led by some megacap growth stocks, as investors awaited economic data in a holiday-shortened week to gauge the Federal Reserve's policy path.

Tesla gained 3.66% after CEO Elon Musk unveiled the electric-vehicle maker's one-month trial of its Full Self-Driving technology to existing and new customers in the United States. The stock is up nearly 5% for the week but remains down nearly 28% for the year.

Other index boosters included heavyweights Alphabet , up 0.99%, and Meta Platforms, which gained 0.43%.

The focus remains on a key reading of the Personal Consumption Expenditures Price Index (PCE), the Fed's preferred inflation gauge. The data is due on Friday, when U.S. markets will be shut for the Good Friday holiday.

The index is expected to have risen 0.4% in February and 2.5% annually. Core inflation, which excludes volatile food and energy components, is estimated to have been up 0.3% last month, keeping the annual pace at 2.8%, economists polled by Reuters said.

"The big number is Friday. That's the number everyone's going to pay attention to and whatever happens in the meantime is going to be noise, so I don't anticipate a whole lot happening until we get that data point," said Stephen Massocca, senior vice president at Wedbush Securities in San Francisco.

"The one thing that would be death, death for this market is if somehow something came out that led people to believe that the fed funds rate has not topped out yet. If for some reason people thought the Fed was even giving an inkling to raising rates further, stand out of the way."

On the economic front, orders for long-lasting U.S. manufactured goods increased more than expected in February, while business spending on equipment showed tentative signs of recovery. In a separate report, the Conference Board said its consumer confidence index was little changed at 104.7 in March.

The Dow Jones Industrial Average rose 86.40 points, or 0.22%, to 39,400.00. The S&P 500 gained 10.25 points, or 0.20%, at 5,228.54 and the Nasdaq Composite added 42.96 points, or 0.26%, to 16,427.65.

The three major U.S. indexes hit record highs last week after the Fed maintained its projection for three interest-rate cuts this year.

Markets have been slowly increasing expectations the central bank will cut rates by at least 25 basis points in June, currently pricing in a 70.4% chance, the CME's FedWatch Tool showed, up from 59.2% last week.

Trump Media & Technology group surged 46.97% as it kicked off its first day of trading after completing a reverse merger with a blank check firm.

McCormick added 9.68% as the best performer on the S&P 500 after the spice maker beat market expectations for first-quarter sales and profit.

Seagate Technology gained 9.07% after Morgan Stanley upgraded the computer hard-drive maker's rating to "overweight" from "equal-weight."

Trading volumes are expected to be light, and thin out as the holiday approaches.

Advancing issues outnumbered decliners by a 1.3-to-1 ratio on the NYSE and by a 1.07-to-1 ratio on the Nasdaq.

The S&P 500 posted 30 new 52-week highs and one new low while the Nasdaq recorded 105 new highs and 110 new lows.

(Reporting by Chuck Mikolajczak; Editing by Richard Chang)