By Noel Randewich and Ankika Biswas

NEW YORK (Reuters) -The Nasdaq and S&P 500 hit record highs on Wednesday fueled by gains in Nvidia (NASDAQ:NVDA) and other Wall Street heavyweights ahead of inflation data and quarterly earnings reports due this week.

It was the fifth straight day of intraday record highs for the S&P 500 and the Nasdaq. The S&P 500 crossed 5,600 for the first time as expectations of an interest-rate cut in September climbed following comments this week by Federal Reserve Chair Jerome Powell.

Powell said in his second day of Congressional testimony that he was not ready to conclude that inflation was moving sustainably down to 2%, although he expressed "some confidence of that".

The Philadelphia semiconductor index jumped 2% to a record high after contract manufacturer Taiwan Semiconductor Manufacturing Co posted strong quarterly revenue.

"TSMC's report supported the AI narrative, so that more than anything else today is a pretty important data point," said Thomas Martin, senior portfolio manager at Globalt Investments in Atlanta.

Micron Technology (NASDAQ:MU) rallied almost 4%, while Nvidia rose 2.3% to a three-week high.

Apple (NASDAQ:AAPL) climbed 1.4% to a record high, lifting its stock market value to almost $3.6 trillion.

Of the 11 S&P 500 sector indexes, 10 rose, led by information technology, up 1.24%, followed by a 0.97% gain in materials.

With just a handful of large-cap stocks fueling Wall Street's rally this year, some investors worry about a potential selloff if those companies' earnings fail to meet high expectations.

The S&P 500 was up 0.69% at 5,615.50 points.

The Nasdaq gained 0.99% to 18,610.88 points, while the Dow Jones Industrial Average was up 0.48% at 39,482.11 points.

U.S. inflation data due this week include the Consumer Price Index on Thursday and the Producer Price Index report on Friday.

Expectations of a 25-basis-point rate cut by September ticked up to 74% from around 70% on Tuesday and 45% a month ago, according to CME's FedWatch.

Second-quarter earnings season, which kicks off this week with major banks reporting on Friday, will test whether high-flying megacaps can justify expensive valuations and extend their strong runs.

Intuit (NASDAQ:INTU) dropped 3% after the TurboTax owner said it plans to lay off about 10% of its workforce.

Gene-sequencing equipment maker Illumina (NASDAQ:ILMN) jumped 6.5% on plans to acquire privately held Fluent (NASDAQ:FLNT) BioSciences.

Advancing issues outnumbered falling ones within the S&P 500 by a 2.3-to-one ratio.

The S&P 500 posted 27 new highs and 10 new lows; the Nasdaq recorded 54 new highs and 104 new lows.