US stocks Wednesday finished a turbulent day in the red, rallying somewhat from a huge midday drop spurred by worries over global economic weakness and the Ebola epidemic.
The Dow Jones Industrial Average fell 173.45 points (1.06 percent) to 16,141.74. The blue-chip index had fallen more than 400 points earlier in the session.
The broad-based S&P 500 dropped 15.21 (0.81 percent) to 1,862.49, while the Nasdaq Composite Index lost 11.85 (0.28 percent) at 4,215.32.
The main indices were in negative territory throughout the session, with swings in stocks accompanied by big moves in other markets. Equity markets in Britain, France and Germany closed more than two percent lower, while yields on US Treasury bonds also sank below key benchmarks before rallying.
"We haven't seen this level of volatility since 2011," said Tyson McCabe, senior director of advisory services at Nasdaq.
"There are so many different data points coming in, being Ebola or some of the weak US data points, that market participants are really struggling with where to get their read from."
Stocks fell sharply soon after the markets opened following disappointing reports on US retail sales and producer prices.
Equity markets then cut their losses but plunged again midday soon after US health officials warned of more potential Ebola cases after a second health care worker in Dallas was diagnosed with the virus.
Stocks began paring their losses again soon after the Federal Reserve's Beige Book said the US economy continues to grow at about the same modest pace of recent months.
The market's lurches lifted some investments, such as the Russell 2000, a closely watched small cap index, which rose 1.0 percent.
But "there is more negative than positive," McCabe said.
Bank of America fell 4.6 percent after it reported a $70 million third-quarter loss due to a $5.3 billion charge on legal expenses following a mortgage-securities settlement.
Other financial equities suffered deep losses, including Dow member JPMorgan Chase (-4.2 percent), Citigroup (-3.5 percent) and Wells Fargo (-2.0 percent).
Dow member Wal-Mart Stores fell 3.6 percent after cutting its full-year sales forecast to two-three percent from the previous range of three-five percent.
Bond prices leaped higher. The yield on the 10-year US Treasury dropped to 2.09 percent from 2.21 percent Tuesday after earlier falling below two percent for the first time during a trading session since June 2013.
The 30-year Treasury fell to 2.88 percent from 2.96 percent. Bond prices and yields move inversely.