U.S. stocks opened lower, with the blue-chip Dow index weighed down again by losses in UnitedHealth Group.

UnitedHealth Group is under a Department of Justice criminal probe for possible criminal Medicare fraud related to its Medicare Advantage business, according to the Wall Street Journal . The company said it had not been informed of a criminal probe by federal prosecutors, Reuters said. UnitedHealth's stock tumbled 16%.

At 10 a.m. ET, the Dow shed 0.31%, or 129.75 points, to 41,921.31; the broad S&P 500 dipped 0.18%, or 10.73 points, to 5,881.85; and tech-heavy Nasdaq fell 0.52%, or100.05 points, to 19,046.76. On Wednesday, the broad S&P 500 just barely registered its third consecutive win as investors remained upbeat about the China-U.S. trade deal announced on Monday.

The benchmark 10-year Treasury yield fell to 4.485%, and oil prices dipped after President Donald Trump said a deal with Iran on nuclear weapons was pending. A deal could lead to easier crude sanctions on the middle eastern country.

Better news came from retail giant Walmart, which topped analysts' earnings expectations in the first three months of the year, showing it could weather the tariff storm. It also held onto its full-year outlook. However, Chief Financial Officer John David Rainey said consumers could start to see higher prices as soon as later this month. Walmart shares shed 3.57%.

Big tariff effects not present yet

Major tariff effects still aren't showing up in April data, economists said.

April's producer price index (PPI) unexpectedly fell 0.5% in April from the prior month, led by a 0.7% decline in services and the largest drop on record for that measure. PPI measures wholesale inflation, or prices businesses pay for their goods and services. Economists polled by Dow Jones had anticipated April PPI grew by 0.3% from the prior month.

Separately, April retail sales edged up 0.1%, also better than estimates for sales to be unchanged and off March's revised 1.7% jump, which was the biggest monthly surge since early 2023. Retail sales data are seen as a gauge of how consumers are dealing with tariff fears and economic uncertainty.

April retail sales were led by restaurant spending, "a sign that consumers are willing to allocate toward discretionary spending," said Jeffrey Roach, chief economist for LPL Financial.

Jamie Cox, managing partner for Harris Financial Group, said "if you are in the stagflation camp, these data aren’t confirming your thesis. While growth is slowing, disinflation remains intact."

Federal Reserve Chairman Jerome Powell noted this morning in prepared remarks at a conference how more frequent and potentially more persistent supply shocks affecting the economy could mean higher longer-term rates.

Corporate news

Cryptocurrency

Crypto exchange Coinbase said in a regulatory filing cyber criminals bribed overseas staff to steal customer data and trick customers into sending them funds. The incident may cost Coinbase up to $400 million to fix, the company estimated.

“Cyber criminals bribed and recruited a group of rogue overseas support agents to steal Coinbase customer data to facilitate social engineering attacks,” the company said in a blog post . “These insiders abused their access to customer support systems to steal the account data for a small subset of customers. No passwords, private keys, or funds were exposed and Coinbase Prime accounts are untouched. We will reimburse customers who were tricked into sending funds to the attacker.”

Coinbase shares fell more than 5.5%.

Bitcoin was last down 1.39% at $102,119.80.

This story was updated with new information.

Medora Lee is a money, markets, and personal finance reporter at USA TODAY. You can reach her at mjlee@usatoday.com and subscribe to our free Daily Money newsletter for personal finance tips and business news every Monday through Friday.

This article originally appeared on USA TODAY: US stocks open lower, with UnitedHealth decline weighing on Dow