NEW YORK (AP) — A late-afternoon rally reversed steep losses for U.S. stocks Friday, lifting the Dow Jones industrial average more than 300 points and capping a turbulent week on Wall Street that left the market with its steepest weekly slide in two years.

The big point swings that pummeled stocks reflected a return of volatility after an unprecedented period of calm. Until this week, the market had not endured a 5 percent drop since January 2016.

“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,” said Terry Sandven, chief equity strategist at U.S. Bank Wealth Management.

The swiftness of the market’s slide into a correction, or a drop of at least 10 percent from a recent peak, was unparalleled. The Standard & Poor’s 500 index, the benchmark for many index funds, took only nine days to fall 10 percent from its all-time high on Jan. 26.

“The S&P 500 hasn’t moved into correction mode this quickly, ever,” said Lindsey Bell, investment strategist at CFRA Research.

Since hitting that high last month, the S&P 500 has lost about $2.49 trillion.

For a while Friday, it was anybody’s guess whether the weeklong sell-off would ease or worsen. Stocks struggled to stabilize 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 Dow Jones briefly sank 500 points after surging more than 349 points earlier in the day and then swung to a 330-point gain in the final hour of trading. The blue chip average suffered its second 1,000-point drop in a week on Thursday.

At one point, the market was on pace for its worst weekly decline since October 2008, at the height of the financial crisis.

“History does show that, even though we haven’t seen this quick of a movement from a peak to correction mode, what we do know is the swifter the way down, the sooner the market will bottom and start moving up,” Bell said.

All told, the S&P 500 rose 38.55 points, or 1.5 percent, to 2,619.55 Friday. The Dow gained 330.44 points, or 1.4 percent, to 24,190.90. The Nasdaq composite added 97.33 points, or 1.4 percent, to 6,874.49.

The three indexes finished the week down more than 5 percent. They’re also now all in the red for the year.