Sell-off of stocks continues a volatile stretch, as Ukraine adds to investors’ worries.

Stocks slid on Thursday, continuing a volatile stretch of trading brought on by uncertainty about inflation, rising interest rates and the potential for war in Europe.

The S&P 500 fell as much as 2.1 percent, dropping into negative territory for the week, while the Nasdaq composite was down 2.7 percent.

Tech companies were some of the worst performers, with Alphabet, Google’s parent, and Meta, Facebook’s parent, down more than 3 percent. Microsoft was down more than 2.5 percent.

Tesla, one of the largest companies in the S&P 500, dropped about 5 percent. The main auto-safety regulator in the United States said it was investigating reports from Tesla’s customers of “phantom braking” when they were using their vehicles’ driver-assistance system.

Shares of banks also fell, with Morgan Stanley dropping more than 4.5 percent and Wells Fargo losing 3.6 percent.

Concerns over the prospect of a Russian invasion of Ukraine have weighed on global markets. On Tuesday, the stock market finished the day higher after Russian officials announced a partial troop withdrawal from the Ukrainian border. But President Biden said on Thursday that the possibility of an invasion remained “very high,” and shelling between Ukraine and Russia-backed separatists spiked, raising concerns that the conflict was heating up.

“Markets are concerned about the Russian troop buildup and a lack of trust in Putin’s declaration that they are beginning to remove troops from the region,” said Chris Zaccarelli, the chief investment officer for Independent Advisor Alliance, an investment advisory firm.

Investors have also been anticipating that the Federal Reserve will increase interest rates as it looks to fight persistently high inflation. Raising the Fed’s policy rate can lead to higher interest rates for houses and cars, causing spending to slow and inflation to moderate. But it also can increase the return on bonds, making riskier investments like stocks less appealing.

Minutes released on Wednesday from the Fed’s January meeting showed that most officials agreed that they might need to withdraw their support for the economy even more quickly if inflation does not cool down as they expect. Investors are now anticipating that the Fed’s policy rate could rise to more than 1.75 percent by the end of the year, up from nearly zero.

Yields on the 10-year Treasury note, which last week crossed 2 percent for the first time since 2019, fell about seven basis points, or 0.07 percentage points, to 1.97 percent. Yields fall as prices for bonds rise, which can happen when investors move money out of riskier investments like stocks.

“The concerns for growth going forward and recession risks are new to traders’ minds,” said Edward Moya, a senior market analyst at Oanda. “There’s a lot of fear that the optimistic growth outlook for 2023 is up in the air.”

But the broad nature of Thursday’s sell-off pointed to more than one trigger. Oil has been trading at prices not seen since 2014, and an invasion by Russia, a big oil producer and Europe’s largest supplier of natural gas, would almost certainly push energy prices higher. But on Thursday, oil fell, with West Texas Intermediate, the U.S. crude benchmark, down 2 percent, to about $91.76 a barrel. Natural gas fell more than 4 percent.

The consumer staples sector was one of the few that did not fall on Thursday. Walmart was one of the best-performing companies in the S&P 500, climbing 3.6 percent after it reported that its revenue rose to $152.9 billion, up 0.5 percent in the three months ending in January from a year earlier. The company also said that sales across its U.S. business increased 5.7 percent to about $105 billion in the quarter.

AutoNation rose 3.8 percent after the company reported a profit of $387 million in its latest quarter, while revenue rose 14 percent to $6.6 billion.

In Europe, stock indexes edged lower. The Stoxx Europe 600 fell 0.7 percent on Thursday. Asian markets closed mixed.