U.S. stocks closed mixed on Wednesday following strong quarterly results from Microsoft (MSFT) and Alphabet (GOOGL) that kicked off a big tech earnings bonanza this week. Investors were also hit with a fresh wave of concern about the health of regional banks.

The S&P 500 (^GSPC) closed down 0.39% as First Republic Bank’s (FRC) stock sank on Wednesday. The Dow Jones Industrial Average (^DJI) dipped 0.68%. The technology-heavy Nasdaq Composite (^IXIC) was up 0.47%, paring earlier gains after tech giants Microsoft and Alphabet both reported better-than-expected earnings and revenue for the most recent quarter after the close on Tuesday.

Government bondswere up. The yield on the 10-year note ticked up to 3.44%, while rate-sensitive two-year note yield rose slightly to 3.93%.

Microsoft rallied more than 7% after the software giant reported fiscal third-quarter earnings that surpassed estimates on Tuesday, indicating growing strength in its AI and cloud businesses. Microsoft earned $2.45 a share, on revenue of $52.9 billion, compared to a profit of $2.22 a share, on $49.4 billion for the same period a year ago.

Microsoft's potential acquisition of Activision Blizzard (ATVI), however, suffered a setback Wednesday morning, as UK regulators blocked the deal over competition fears. Activision stock was down about 12%.

Alphabet’s first-quarter earnings showed a 2% rise in search revenues, far below the corresponding quarters from the last two years. Meanwhile, installations of the Bing app have quadrupled after it was augmented by AI. Shares were down Wednesday afternoon.

Meta (META) earnings are up next after the bell on Wednesday, while Amazon (AMZN) reports Thursday.

Tech stocks have fueled the equities rally so far this year, but some analysts expect the sector could come under selling pressure as it loses steam. Investors remain concerned that expectations for earnings growth will be weaker, prompting some market strategists to anticipate a pullback that has so far not yet materialized.