June 26 (Reuters) - Wall Street's main indexes ended lower on Friday, after shares of AI-related chipmakers fell sharply despite significant gains in Moderna and other healthcare stocks.

The Philadelphia Semiconductor Index fell, highlighting the latest volatility among AI-related chipmakers that have been the main driver of Wall Street's gains in the past few years.

Some investors are concerned that the massive spending on building AI data centers may take a long time before it pays off, but others remain optimistic about AI's ability to generate higher profits.

David Stubbs, chief investment strategist at AlphaCore Wealth Advisory, said, "It's too early to conclude that a major correction in the technology sector is likely, but what I would say is that the questions about profitability and the capital expenditure story are certainly not going away."

Stubbs warned that Wall Street could be vulnerable to any signs that U.S. companies may not be able to meet investors' high expectations for earnings.

Apple's stock rebounded, partly due to a sell-off on Thursday when it raised prices for iPads and MacBooks, citing higher costs for memory chips and storage.

Shares in Moderna rose to their highest level since 2024 after the drug development company held an investor event and showcased its projects under development.

Data released on Thursday showed that the US inflation rate rose to over four percent in May, as the Iran war drove up energy prices, keeping alive the possibility of the Federal Reserve (the US central bank) raising interest rates.

Preliminary data indicates that the S&P 500 closed down 19.81 points, or 0.27 percent, at 7,337.68, while the Nasdaq Composite lost 121.72 points, or 0.48 percent, to close at 25,236.88. The Dow Jones Industrial Average fell 125.78 points, or 0.23 percent, to 51,794.84.

A report that OpenAI is considering delaying its initial public offering until next year has negatively impacted risk sentiment related to artificial intelligence stocks.