Updates prices

By Twesha Dikshit and Utkarsh Hathi

May 27 (Reuters) - U.S. stock index futures extended gains on Wednesday, helped by sustained AI-driven momentum, while investors were cautiously optimistic that the U.S. and Iran would reach a deal.

A fragile truce between Tehran and Washington remained in place despite recent U.S. strikes near the Strait of Hormuz, which Iran called a "gross violation" of the ceasefire agreement.

"The evolving situation in the Middle East and still-elevated bond yields may put the global stock rally to the test. Bouts of market volatility remain likely, as investors react to fresh headlines," UBS analysts said.

"But we also think strong earnings should support further gains for equities over the medium term, and we see attractive opportunities across regions."

At 06:34 a.m., Dow E-minis YMcv1 were up 228 points, or 0.45%, and S&P 500 E-minis EScv1 were up 23 points, or 0.31%. Nasdaq 100 E-minis NQcv1 were up 144 points, or 0.48%.

Both the S&P 500 .SPX and the Nasdaq .IXIC closed at record highs on Tuesday, driven by renewed confidence around AI, as Micron surpassed $1 trillion in market value for the first time.

Shares of the memory chipmaker MU.O gained 5.8% in premarket trading. Peers SanDisk SNDK.O, Western Digital WDC.O and Seagate Technology STX.O were up between 1.7% and 2.3%.

A strong earnings season and expectations of about 29% year-on-year growth in the first quarter have aided the rally on Wall Street, with the blue-chip Dow Jones .DJI becoming the last major index to hit a record high on Friday.

Goldman Sachs raised its 2026 year-end forecast for the S&P 500 to 8,000 from 7,600, citing continued strength in corporate earnings.

Markets will next look toward the personal consumption expenditures index data on Thursday. The Federal Reserve's key inflation measure could provide fresh clues on the monetary policy path forward under new chair Kevin Warsh.

Money markets currently expect the Fed to keep rates steady for the rest of the year, with some pricing in a 25 basis point hike in December.

Among early movers, Zscaler ZS.O tumbled 23.9% after the cloud security firm projected fourth-quarter revenue below expectations.

GlobalFoundries GFS.O fell 6.9% after Bloomberg News reported majority owner Mubadala Investment Company was seeking to raise $1.91 billion from an unregistered block sale of GFS shares.

U.S.-listed shares of Chinese e-commerce firm PDD Holdings PDD.O slipped 5% after reporting quarterly revenue below estimates.