US benchmark equity indexes were lower intraday, weighed down by a selloff in Nvidia (NVDA) shares, as markets analyzed the latest manufacturing sector data.

The Nasdaq Composite was down 1.1% at 18,632.7 after midday Monday, while the S&P 500 fell 0.8% to 5,905.4. The Dow Jones Industrial Average dropped 0.7% to 43,520.8. Among sectors, energy saw the biggest decline, while real estate paced the gainers.

In economic news, two surveys painted a mixed picture of the US manufacturing sector in February, with the Institute for Supply Management's data pointing to a slower expansion rate sequentially and S&P Global (SPGI) indicating the best growth rate since June 2022.

The ISM survey showed that price pressures are likely "stirring again" in the production pipeline, BMO Capital Markets said. "This is not what the (Federal Reserve) wants to see -- especially at a time when firms could soon potentially be dealing with the impact of major tariffs."

The exact US tariff that will be levied against Canada and Mexico starting Tuesday is "fluid," Commerce Secretary Howard Lutnick reportedly said Sunday, implying it could be lower than the originally planned 25%. The additional 10% duty on Chinese imports is "set," according to Lutnick.

US Treasury yields were down intraday Monday, with the 10-year dropping 5.3 basis points to 4.18% and the two-year rate losing one basis point to 3.99%.

In company news, Nvidia shares were down 7%, the steepest decline on the Dow and among the worst on the S&P 500 and the Nasdaq. Servers linked to a fraud case in Singapore may have included Nvidia chips and were supplied by Dell Technologies (DELL) and Super Micro Computer (SMCI) to local companies before being delivered to Malaysia, news outlets reported, citing Singapore's Home Affairs and Law Minister K. Shanmugam.

Dell shares were down 4.4% intraday, while Super Micro slumped 8.7%, the worst S&P 500 performer.

Verizon (VZ) was the top gainer on the Dow, up 1.2%. Lockheed Martin (LMT) said Sunday it is partnering with Nokia (NOK) and Verizon to incorporate Nokia's 5G technology into its 5G.MIL Hybrid Base Station, which connects commercially available 5G with military communication systems.

Lockheed Martin was up 0.7% intraday Monday, while Nokia's US-listed shares jumped 5.4%.

West Texas Intermediate crude oil was down 2.2% at $68.23 a barrel.

Policymakers have "more work to do" to achieve price stability, with inflation still above their 2% target, St. Louis Fed President Alberto Musalem said. "I believe a patient policy approach now will help us as we seek maximum employment, price stability and a durable economic expansion."

Gold was up 1.8% at $2,899.30 per troy ounce, while silver jumped 2.5% to $32.28 per ounce.