(Updated - May 21, 2024 11:56 AM EDT)

-- Main U.S. indexes traded largely flat Tuesday, as investors reacted with caution ahead of more speeches from Federal Reserve officials about the potential for future interest rate cuts.

Here are some of the biggest U.S. stock movers today:

Lowe’s (NYSE:) stock fell 3% despite the home improvement retailer reporting first-quarter net sales that topped expectations, boosted by growth in its online offerings and services for professionals. Concerns about margins weighed on sentiment.

Palo Alto Networks (NASDAQ:) stock fell 4% after the cybersecurity firm’s latest billings forecast disappointed elevated expectations, with the company facing weakness in spending by clients concerned by an uncertain economic environment.

Macy’s (M) stock fell 1% despite the department store’s first-quarter earnings topped expectations.

Nvidia (NASDAQ:) stock was choppy ahead of results on Wednesday. AWS reportedly halted orders as it awaits the release of Nvidia's newest AI chips.

Xpeng (NYSE:) stock rose 7% after the Chinese electric-vehicle maker reported better-than-expected first-quarter numbers, despite the very competitive market.

Peloton (NASDAQ:) stock fell 13% after the integrated fitness company launched a $1 billion loan to refinance existing debt.

Zoom (NASDAQ:) stock were volatile after the video conferencing giant--a pandemic-era favorite--unveiled a broadly cautious outlook for its current quarter and fiscal year. Shares pared an earlier decline and were higher by 1.5% midday.

AstraZeneca (NASDAQ:) ADRs rose 2.3% after the pharmaceutical giant announced it now expects to post $80 billion in total revenue by the beginning of the next decade, after sales of $45.8 billion in 2023.

(NYSE:) fell 10% after issuing third quarter outlook that disappointed Wall Street.

Microsoft (NASDAQ:) rose 1.5%, hitting a 52-week high, ahead a highly anticipated presentation today. The focus is expected to be on its latest AI developments.

Dollar General (NYSE:) rose 4% after analysts at Citi previewed its first quarter results and said they don't see signs of a slowdown. It's scheduled to report on May 30.

Additional reporting by Louis Juricic