U.S. stocks fell on Friday after the trial result from Johnson & Johnson's coronavirus vaccine disappointed some investors, while worries about retail trading frenzy persisted.
The Dow Jones Industrials weakened 178.96 points to begin Friday at 30,424.40.
The S&P 500 dropped 15.98 points to 3,771.40, as eight of the 11 sectors traded in the red.
The NASDAQ slid 37.82 points to 13,299.34.
All three major averages have lost at least 1% this week.
JNJ said its one-dose vaccine demonstrated 66% effectiveness overall in protecting against Covid-19. The vaccine was 72% effective in the United States, 66% in Latin America and 57% in South Africa after four weeks, the company said. The vaccine offered complete protection against COVID-related hospitalizations. Shares of JNJ dropped 3.6%.
Stocks had rallied to record highs on the hope that vaccines would be effective against Covid to allow a smooth economic reopening before the end of the year. New mutations more resilient to vaccines could upend that rosy outlook for investors.
Heightened speculative trading by retail investors also continued to unnerve the market. Shares of GameStop doubled shortly after the open after Robinhood said it would allow limited buying of the stock and other heavily shorted names after restricting access the day before.
Robinhood raised more than $1 billion from its existing investors overnight, in addition to tapping bank credit lines, to ensure it had the capital required to allow some trading again in the volatile stocks. The stock last traded up 60%.
Investors are concerned that if GameStop continues to rise in such a volatile fashion, it may ripple through the financial markets, causing losses at brokers like Robinhood and forcing hedge funds who bet against the stock to sell other securities to raise cash.
Prices for 10-Year Treasurys dropped, raising yields to 1.08% from Thursday's 1.05%. Treasury prices and yields move in opposite directions.
Oil prices restocked 59 cents to $52.93 U.S. a barrel.
Gold prices recovered $22.00 to $1,859.90 U.S. an ounce.