Here we go again. Worries about the bond market are driving another wave of selling on Wall Street.
The Dow dropped more than 1,000 points on Thursday as investors focused on concerns about inflation and higher interest rates.
Stocks recovered modestly, and the Dow was down about 400 points, or 1.6%, later in the afternoon. The S&P 500 and Nasdaq also lost more than 1% apiece.
The market started the day just modestly lower, but stocks fell sharply as the 10-year Treasury yield briefly hit a four-year high of 2.88%, renewing concerns about inflation and higher interest rates.
"The bond market has definitely got the stock market's attention," said Ryan Detrick, senior market strategist at LPL Financial. "Is the bond market telling us something we don't know? Is there more inflation down the road than we're expecting?"
The latest round of selling knocked the Dow and S&P 500 back into the red for the year. All of the Nasdaq's gains for 2018 were also wiped out.
Wall Street has failed to stage a lasting rebound from Monday, when fears about the bond market sent the Dow plunging a record 1,175 points.
Trading has been extremely choppy, and the market has swung in wide ranges. The Dow surged 567 points on Tuesday, but a 381-point rally vanishedon Wednesday after bond yields crept higher.
"A big down day like Monday doesn't just go away. We're going to continue to see volatile days," said JJ Kinahan, chief market strategist at TD Ameritrade. "It can take two to three weeks to work through the system."
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It's a big shift from 2017 and the beginning of 2018, when the stock market went the longest period ever without tumbling. But such calm is unusual, and stocks overheated.
"We had an epic run. There was euphoria because there hadn't been a pullback," said Jeffrey Schulze, investment strategist at ClearBridge Investments.
Consider this: The S&P 500 has risen or fallen 1% five times in the past two weeks. That only happened eight times all of last year, the fewest since 1964, according to LPL.
"We've hit this incredible dose of volatility like nothing we've seen since Brexit," Detrick said.
The yield on the 10-year Treasury bond ticked higher again on Thursday morning, to 2.88%. That's a big spike from just 2.65% during the panic selling Monday afternoon. However, a flight to safety away from stocks and back into government bonds knocked the 10-year back down to 2.82% by early afternoon.
The bull market has feasted on extremely low bond rates. The fear is that Treasury yields will rise to levels that make stocks less attractive and force the Federal Reserve to fight inflation by aggressively raising interest rates.
New York Federal Reserve President Bill Dudley told Bloomberg News on Thursday that if the U.S. economy keeps getting stronger the central bank may be justified in raising rates four times this year. Wall Street has been expecting three rate hikes at most.
Dudley, who called the market slump "small potatoes," said the "jury is still out" on the number of rate hikes.
Washington is putting more pressure on rates. The U.S. Senate reached a bipartisan deal Wednesday that would boost spending limits by $300 billion over the next two years. The compromise, coupled with Republican tax cuts, could lift the federal budget deficit to $1.07 trillion in fiscal 2019, according to Bank of America estimates.
Wall Street anticipates that more government spending will force the Treasury Department to borrow more money by selling additional bonds. To drum up demand for that higher supply, rates may have to go up.
Bank of America analysts warned that the Senate agreement will contribute to "higher rates" and raise "risks for tighter overall financial conditions."
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These bond market worries briefly sent the Dow into a correction earlier this week, a 10% decline from recent highs. The fragile rebound lifted the market a bit, and the Dow and S&P 500 are now about 8% off their from all-time highs. Neither index has closed in a correction in two years.
The stock market is still up dramatically since President Trump's election. His promises for big corporate tax cuts helped lift the Dow more than 8,000 points, though it has since given back about a fifth of that surge.
The market performance also reflects the strong U.S. and global economies, which have boosted corporate profits. The job market remains healthy, as evidenced by a report Thursday that applications for unemployment benefits are at a 45-year low.
"The U.S. economy is on solid foundation," said ClearBridge's Schulze.
--CNNMoney's Donna Borak contributed to this report.
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