US stocks have tumbled again, deepening the losses felt earlier this week.
The Dow Jones Industrial Average closed down 1,032 points (or 4.15%), meaning it is 10% down from the record high it reached two weeks ago.
This also puts it in what is known on Wall Street as a "correction".
It is the second-worst fall in history, eclipsed only by Monday's 1,175-point plunge.
The broad-based S&P 500 dropped 100 points or 3.75%, and the tech-rich Nasdaq was down 3.9%.
Stocks began to fall in early trading and their losses grew throughout the day.
Technology companies and banks were the big losers, with Microsoft and JP Morgan Chase both losing 1.7%.
Analysts blamed higher treasury bond yields for Thursday's poor performance, also saying the market has become too expensive and was due for correction.
But the other big worry is that the US Federal Reserve Bank will raise interest rates too quickly.
Scott Wren, senior global equity strategist for Wells Fargo Investment Institute, said: "Far and away the most important things are the fear that the Fed is going to make a mistake, and higher wages are going to cut into margins."
The turmoil began late last weekamid fears of increasing inflation,when the Dow lost 1,175 points – the biggest one-day points loss in its 122-year history.
Thursday's losses were steady, rather than the sharp falls seen over the past few days, however.
Jonathan Corpina, senior managing partner for Meridian Equity Partners in New York, told Reuters: "The dust hasn't settled yet, and I think both buyers and sellers are trying to figure out what this market really wants to do.
"I would think that this continues to happen for the next few trading sessions for everything to kind of get flushed out."
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European markets were also down on Thursday, after the Bank of England said it could raise interest rates in the coming months.
The FTSE 100 fell 1.5% after the Bank warned rates could head upwards sooner and faster than previously thought.