Updates with afternoon trading

By Noel Randewich

May 8 (Reuters) - The S&P 500 and the Nasdaq rallied to record highs on Friday, boosted by gains in Nvidia, Sandisk and other AI-related stocks, while a stronger-than-expected jobs report pointed to labor market resilience.

Nvidia NVDA.O climbed 1.8%, while memory and storage sellers Micron Technology MU.O and Sandisk SNDK.O both rallied about 12%, lifted by strong demand from the rapid buildout of AI data centers. Still, despite the tech rally, most sectors in the S&P 500 were down for the day.

The Philadelphia SE Semiconductor index .SOX jumped almost 5%, bringing its gain so far in the second quarter to 54%.

The S&P 500 and the Nasdaq have surged to record highs this week as investors focused on strong financial reports from U.S. companies, setting aside concerns that high oil prices related to the Middle East conflict are fueling inflation.

First-quarter S&P 500 earnings are on track to climb almost 29% year-over-year, with much of that growth fueled by Wall Street's AI-related heavyweights, according to LSEG I/B/E/S.

"This is an economy that seems hard to wreck," said Rob Williams, chief investment strategist at Sage Advisory Services in Austin, Texas. "It's the productivity story, the spending, the consumer wealth effect and the earnings."

Data showed U.S. employment increased more than expected in April and the unemployment rate held steady at 4.3%, reinforcing expectations that the Federal Reserve would leave interest rates unchanged for some time.

Traders expect the central bank will hold interest rates steady in the 3.50% to 3.75% range until the end of the year.

The S&P 500 was up 0.83% at 7,397.72 points. The Nasdaq gained 1.54% to 26,202.53 points, while the Dow Jones Industrial Average was up 0.04% at 49,618.14 points.

The S&P 500 tech index .SPLRCT rallied 2.5%. Yet even as the broader market rose, six of the 11 S&P 500 sector indexes declined. Healthcare .SPXHC was down 0.7%, leading the decliners, followed by a 0.49% loss in financials .SPSY.

The S&P 500 and the Nasdaq were on track for a sixth straight week of gains, which would be the longest such winning streak since October 2024. The Dow was set for a second consecutive week of advances.

The earnings optimism helped investors look past fresh attacks between U.S. and Iranian forces in the Gulf.

Brent crude LCOc1 rose above $100 a barrel as hopes faded for a quick resolution to the Middle East conflict and the gradual reopening of the Strait of Hormuz, a key transit route for oil and liquefied natural gas.

The U.S. said it expected a response from Tehran to its latest proposal later on Friday.

Of the 440 S&P 500 companies that have reported first-quarter results so far, 83% have topped analysts' earnings estimates, according to LSEG. That compares with a long-term average of about 67%.

However, there have been some earnings disappointments.

Cloudflare NET.N plunged 23% after the cloud services company said it would cut about 20% of its workforce and forecast second-quarter revenue slightly below Wall Street expectations.

Trade Desk TTD.O fell 5.7% after the ad-tech firm forecast second-quarter revenue below Wall Street estimates.

CoreWeave CRWV.O dropped 12% after the cloud infrastructure technology company raised the lower end of its annual capital expenditure forecast, citing a rise in component costs.

Online travel platform Expedia EXPE.O slipped 6.5% after it flagged the conflict in the Middle East was weighing on demand.

Declining stocks outnumbered rising ones within the S&P 500 .AD.SPX by a 1.1-to-one ratio.

The S&P 500 posted 28 new highs and 23 new lows; the Nasdaq recorded 122 new highs and 103 new lows.