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* Futures off: Dow 0.01%, S&P 0.02%, Nasdaq 0.02%

March 19 (Reuters) - U.S. stock index futures were little changed on Tuesday as investors remained cautious ahead of the start of the Federal Reserve's meeting.

Dow e-minis were down 5 points, or 0.01%, at 05:02 a.m. ET. S&P 500 e-minis were down 1.25 points, or 0.02% and Nasdaq 100 e-minis were down 4.5 points, or 0.02%.

Wall Street closed higher on Monday, with the Nasdaq bouncing back from two small weekly losses, as growth stocks such as Alphabet and Tesla boosted the tech-heavy index.

Most megacap growth stocks edged lower in premarket trading.

Investor darling Nvidia struggled for direction after the chipmaker unveiled the Blackwell B200, an AI chip it says is up to 30 times faster than its previous chip. Some investors suggested the news was priced into the high-flying stock.

Fellow chipmaker AMD dipped 1.7%, while Super Micro Computer, which makes AI-optimized servers with Nvidia's chips, fell 1.6%.

All eyes are on U.S. central bankers who are expected to hold rates steady at the end of their two-day meeting on Wednesday.

But, investors are concerned that their new economic projections may be a wild card, potentially signaling fewer interest rate cuts and a later start to the policy easing.

Robust inflation data has pushed traders to pull back bets of the first rate cut coming in June to 55.2% from 71% at the start of last week, according to the CME Fedwatch Tool.

"With price rises still steamier than expected, signs of a more watchful, wary Fed are likely to emerge from this meeting," said Susannah Streeter, head of money and markets, Hargreaves Lansdown.

"However, the wave of exuberance is continuing among investors still charged with enthusiasm about the seemingly infinite possibilities that artificial intelligence will bring to the corporate world."

Among other movers, crypto-exchange operator Coinbase Global and miners Riot Blockchain and Marathon Digital Holdings shed between 4.3% and 6.5%, tracking the sharp slide in bitcoin.

Spire Global rose 18.5% after the company announced a collaboration with Nvidia for AI-driven weather prediction. (Reporting by Bansari Mayur Kamdar in Bengaluru; Editing by Savio D'Souza)