Wall Street has capped a day of wild swings with a late-afternoon rally that reversed steep early losses and sent the Dow Jones industrial average 330 points higher.
Even with the rebound, this was the worst week for the market in about two years.
Stocks struggled to stabilise much of the day as investors sent prices climbing, then slumping in unsteady trading a day after the market entered its first correction in two years.
The up-and-down swings followed a drop of 10% from the latest record highs set by major US indexes just two weeks ago.
At midday, the market was on pace for its worst weekly decline since October 2008, at the height of the financial crisis.
The Dow briefly sank 500 points in afternoon trading after surging more than 349 points earlier in the day.
The blue chip average suffered its second 1,000-point drop in a week on Thursday.
The Standard & Poor’s 500 index, the benchmark for many index funds, also wavered between gains and losses.
As of Thursday, some 2.49 trillion dollars in value had vanished from the index since its most recent peak on January 26, according to S&P Dow Jones Indices.
“Equities have traded in a roller coaster fashion all week and today is no exception,” said Terry Sandven, chief equity strategist at US Bank Wealth Management.
“There’s a fair amount of volatility in the market, and our belief is the volatility is leaving investors riddled with stress and uncertainty, which is likely to continue.”
The S&P 500 rose 38.55 points, or 1.5%, to 2619.55.
The Dow gained 330.44 points, or 1.4%, to 24190.90.
The Nasdaq composite added 97.33 points, or 1.4%, to 6874.49.
Technology companies accounted for most of the broad gains, outweighing losses in energy stocks, which slumped as US crude prices declined, sending the price of oil below 60 dollars a barrel for the first time this year.
Bond prices fell. The yield on the 10-year Treasury rose to 2.85% from 2.83% late on Thursday.
Some companies rose after reporting quarterly results and outlooks that beat Wall Street’s forecasts.
Skechers USA climbed 2.88 dollars, or 7.5%, to 41.06 dollars.
Chipmaker Nvidia added 14.56 dollars, or 6.7%, to 232.08 dollars.
Expedia slumped after its latest earnings fell short of analysts’ expectations.
The travel website’s 2018 outlook also disappointed investors. Its shares sank 19.03 dollars, or 15.5%, to 104 dollars.
The turbulence in US stock indexes followed a broad slide in global markets.
In Europe, Germany’s Dax fell 1.2%, while France’s CAC 40 lost 1.4%.
Asian markets fell more sharply. Tokyo’s Nikkei 225 lost 2.3% and Hong Kong’s Hang Seng gave up 3.1%.