US equity indexes traded mixed after midday Monday as investors weighed trade-tariff developments and an unexpected improvement in a gauge of services.

The Nasdaq Composite slid 0.4% to 17,912.6, and the S&P 500 retreated 0.3% to 5,667.7. The Dow Jones Industrial Average rose 0.1% to 41,353.8 intraday. The S&P 500 headed for its first drop in 10 trading sessions. Most sectors fell, with energy and consumer discretionary pacing the decliners. Communication services and industrials were among a trio of gainers.

In economic news, the Institute for Supply Management's US services index rose to 51.6 in April from 50.8 in March, compared with expectations for a 50.3 print in a Bloomberg-compiled survey. The ISM's reading indicates expansion, matching the Kansas City and the S&P Global indexes but contrasting other regional services data that signaled contraction.

"The comments from the respondents show widespread difficulty in business planning, working around a tariff policy that is constantly changing and unclear," Jefferies Chief US Economist Thomas Simons said in a note. "Few show signs that current activity has slowed significantly, however."

Most US Treasury yields rose intraday, with the 10-year up 3.5 basis points to 4.33% and the two-year rate climbed 1.3 basis points to 3.85%.

Gold futures jumped 2.4% to $3,319.80 per ounce.

President Donald Trump said Sunday on Truth Social he plans to impose a 100% tariff on movies made outside of the US, claiming that the incentives offered to film and produce movies abroad threaten the domestic film industry. Wedbush Securities said in a research note that the extent to which the planned tariffs will apply to Netflix (NFLX) is unclear. Shares of Netflix fell 1.5% intraday.

Meanwhile, the S&P Global US services index was revised downward to 50.8 in April from the 51.4 flash reading, compared with expectations of 51.2 in a Bloomberg-compiled survey.

West Texas Intermediate crude oil futures sank 2.1% to $57.06 a barrel, touching a fresh four-year low on Monday, after OPEC+ said it would speed the return of 2.2 million barrels per day of production cuts with a second-straight monthly supply increase of 411,000 bpd in June.

"As we have stated from the start of his tenure, [Saudi oil minister] HRH Prince Abdulaziz bin Salman strongly believes in active market management, but also the principle that every country must pull its weight," Helima Croft, head of global commodity strategy at RBC Capital Markets, wrote in a note. "He is seemingly not afraid to use his spare capacity to discipline members that breach the OPEC rules-based order based on the March 2020 experience."

In company news, Seaport Global Securities adjusted the share-price target for Delta Air Lines (DAL) to $65 from $50. Shares jumped 3.3% intraday, among the top gainers on the S&P 500.

Tyson Foods (TSN) shares slumped 9% intraday, the third-worst performer on the S&P 500, after fiscal Q2 adjusted earnings beat, while sales were flat from a year ago and missed expectations.

ON Semiconductor (ON) reported a year-over-year slump in Q1 non-GAAP earnings and revenue. Its shares dived 8.6% intraday, the steepest decline on the Nasdaq.