Updates with afternoon trading, adds analyst comments and market details

By Noel Randewich and Joel Jose

June 26 (Reuters) - Wall Street was mixed on Friday, with gains in Moderna and other healthcare stocks, while AI-related chip stocks tumbled from recent highs.

The Nasdaq was on pace for a more than 4% drop for the week and the S&P 500 .SPX was set for a fall of over 1% as high-flying semiconductor companies remained under pressure despite strong earnings from Micron Technology MU.O.

Apple AAPL.O rose 1.5%, rebounding partly from a selloff on Thursday, when it raised iPad and MacBook prices, blaming soaring memory and storage chip costs.

Moderna MRNA.O surged 13% to its highest level since 2024 after the drug developer hosted an investor event and showcased its pipeline.

The S&P 500 healthcare index .SPXHC rose 2.5%, leading gains among the 11 sector indexes.

The PHLX chip index .SOX sank more than 4%, underscoring recent volatility among AI-related chipmakers that have fueled much of Wall Street's gains in recent years. While some investors remain optimistic about the potential for AI to fuel higher profits, others worry that massive spending to build AI data centers may take too long to pay off.

"It's too early to conclude that there's a major correction brewing in tech, but what I would say is that the questions around profitability and the capex story are certainly not going away," said David Stubbs, chief investment strategist at AlphaCore Wealth Advisory.

Stubbs also warned that Wall Street could be vulnerable to signs that U.S. companies may not be able to deliver on investors' high earnings expectations.

U.S. inflation rose above 4% in May, data showed on Thursday, as the Iran war drove up energy prices, keeping alive the possibility of a Fed rate hike.

While oil prices have retreated sharply as the Middle East tensions eased, Apple's newly announced price hikes suggest inflation remains a concern, said Art Hogan, chief market strategist at B. Riley Wealth.

"We saw a similar dynamic during the pandemic, when supply chain disruptions limited access to semiconductors. Now, we're witnessing a comparable supply shock, this time driven by memory, which is creating renewed inflationary pressure," Hogan said.

The S&P 500 was up 0.10% at 7,365.00 points.

The Nasdaq gained 0.03% to 25,366.14 points, while the Dow Jones Industrial Average was down 0.02% at 51,909.81 points.

A report that OpenAI was considering delaying its public debut until next year also weighed on risk sentiment toward the tech space.

Shares of SpaceX SPCX.O were up 1.7%, and trading volume could be heavy before the session ends as passively managed index funds buy the stock ahead of its inclusion in Russell indexes.

Meanwhile, interest rate concerns persisted, with traders pricing in one 25-basis-point rate hike and a near 27% chance of another by year-end, according to LSEG-compiled data.

A survey showed U.S. consumer sentiment rebounded from record lows in June, though households remained worried about the high cost of living.

ON Semiconductor ON.O dropped 24% after agreeing to acquire Synaptics SYNA.O in an all-stock deal valued at about $7 billion. Synaptics shares were near flat.

Advancing issues outnumbered falling ones within the S&P 500 .AD.SPX by a 1.7-to-one ratio.

The S&P 500 posted 28 new highs and 5 new lows; the Nasdaq recorded 191 new highs and 138 new lows.