02:41 PM EDT, 07/19/2024 (MT Newswires) -- US benchmark equity indexes were down intraday amid a selloff in the technology sector as markets weighed the potential impact of a global tech outage following a CrowdStrike ( CRWD ) system update.

The Dow Jones Industrial Average was down 1% at 40,249.8 after midday Friday, while the Nasdaq Composite fell 0.8% to 17,729.4. The S&P 500 lost 0.7% to 5,506.9. Tech saw the biggest drop among sectors, down 1.3%, while health care was the sole gainer.

The CrowdStrike ( CRWD ) system update affected industries from airlines to broadcasters. In a statement, it flagged "a defect found in a single content update for" Microsoft ( MSFT ) Windows hosts.

"We are working with all impacted customers to ensure that systems are back up and they can deliver the services their customers are counting on," CrowdStrike ( CRWD ) said in an update published at 1:25 pm ET.

"This is being billed as the largest overall IT outage in history," Scotiabank said in a note to clients.

Separately, Wedbush said it continues to see CrowdStrike ( CRWD ) as the "gold standard" in cybersecurity despite the incident. "We believe this historical incident will only be a dark chapter for the company and not impact the long-term bull story for the name," the brokerage said in a note to clients.

CrowdStrike ( CRWD ) shares were down 12% intraday, the worst performer on the S&P 500 and the Nasdaq, while Microsoft ( MSFT ) fell 0.8%.

The US 10- and two-year yields rose 4.6 basis points each to 4.23% and 4.51%, respectively.

In other company news, Travelers (TRV) shares dropped 7.3%, among the steepest decline on the S&P 500, after the property and casualty insurer reported stronger-than-expected second-quarter earnings, while earned premiums fell short of analyst estimates.

Intuitive Surgical (ISRG) was the top gainer on the S&P 500 and the Nasdaq, up 8.6%. The robotic surgical systems company late Thursday logged better-than-expected results for the second quarter, driven by double-digit growth in procedure volumes.

Huntington Bancshares ( HBAN ) shares rose 3.4%, the second-best performer on the S&P 500, after the regional bank's second-quarter earnings topped Wall Street's estimates.

West Texas Intermediate crude oil fell 2.8% to $80.50 a barrel.

Gold was down 2.2% at $2,401.81 per troy ounce, while silver lost 2.9% to $29.34 per ounce.