The Nasdaq plunged 8.4% on the week, its worst since November 2008.
The Dow was down 1,655 points or 6.9 percent for the week, the largest weekly loss since October 2008.
Stocks are plunging again on Wall Street, chopping another 600 points off the Dow Jones Industrial average, bringing its losses since Friday to more than 1,900 points.
Stock indexes are meandering up and down in midday trading as the market steadies following two days of steep drops.
After years of gains, USA investors are fleeing stocks, anxious about a range of factors likely to hit corporate profits, including slowing economic growth domestically and overseas. The S&P 500 is on track for its first annual loss in a decade. The VIX Volatility Index was higher at 28.38 for a gain of 2.80 points or 10.95%.
The Nasdaq is down 570.40 points, or 8.3 percent.
Lipper data on Thursday showed investors pulled almost $34.6 billion out of stock funds in the latest week and were heading for the biggest month of net withdrawals on record. Benchmark U.S. crude fell 4.8 percent to $45.88 a barrel in NY, and it has dropped 40 percent since early October.
The index finished the day down 21.9 percent from its August 29 record closing high, exceeding the 20 percent decline considered the threshold for a bear market.
Scott Wren, senior global equity strategist at Wells Fargo Investment Institute, said investors felt Fed Chairman Jerome Powell came off as unconcerned about the state of the US economy, despite deepening worries on Wall Street that growth could slow even more in 2019 and 2020.
Tokyo's Nikkei 225 lost 2.8 percent and Hong Kong's Hang Seng gave up 1 percent.
The S&P 500 fell 36 points, or 1.4 percent, to 2,471.
The Dow Jones dove 2 percent, or some 470 points, on Thursday following US President Donald Trump's threat to shut down the government over border wall funding. Brent crude, the standard for global oil prices, fell 1 percent to $53.82 a barrel in London.
Wall Street's sharp downturn beginning in October has pulled the Nasdaq composite index into what's known as a bear market.
Companies that make and sell consumer goods were doing better than the rest of the market in early trading Friday. Copper lost 0.8 percent to $2.67 a pound. Silver rose 0.3 percent to $14.87 an ounce and copper, which is considered an indicator of economic growth, fell 0.7 percent to $2.70 a pound. Both companies reported weaker sales than analysts were expecting.
The benchmark S&P 500 index ended a brutal week down 7 percent Friday, led by big drops in former market favorites like Facebook and Amazon.
The Dow Jones Industrial Average climbed 120 points, or 0.5 percent, to 22,967. The tech-heavy Nasdaq composite slipped 27 points, or 0.4 percent, to 6,611.