New York - The stock market capped a turbulent week with a big gain Friday, a sign of renewed investor confidence after days of gloomy economic news.

It was the latest large move for a market which, with a few exceptions, has been on a mostly downward track since last month. Stocks have had four weeks of declines, leaving the Standard & Poor's 500 index 6 percent below the record high from Sept. 18.

Investors rode wild market swings for much of the week. The Dow Jones industrial average plunged as much as 460 points Wednesday, then had one of its best days of the year on Friday, when it soared more than 260 points following strong earnings from big-name companies Morgan Stanley and General Electric, as well as some encouraging U.S. economic news.

"We had indiscriminate selling all week, and then today we had indiscriminate buying," said Jack Ablin, chief investment officer at BMO Private Bank in Chicago.

Market watchers have warned investors to expect more volatility than they have been used to in recent months. Their concerns reflect weaker growth in Europe and what it could mean for U.S. corporate profits, as well as plunging oil prices.

The turmoil has not been limited to the floor of the New York Stock Exchange. Bonds, overseas stock markets and commodities prices have all had big moves this week.

"Most of the swings this week were related to fears about global growth and not about the fundamentals of this market," said James Liu, global market strategist at JPMorgan Funds.

The VIX, a measure of how much volatility investors expect in stocks, has risen from 12 in mid-September to as high as 26 this week, above its historical average of around 20. That's still far below the readings of 80 it had at the height of the 2008 financial crisis.

"This volatility, in a way, is purely psychological. This is the market returning to a more normalized behavior," Liu said.

The Dow advanced 263.17 points, or 1.6 percent, to 16,380.41, its second-best day of the year. The Standard & Poor's 500 index rose 24 points, or 1.3 percent, to 1,886.76 and the Nasdaq composite rose 41.05 points, or 1 percent, to 4,258.44.