Nervousness about the spreading coronavirus gripped Wall Street again on Wednesday, and an early rise in stock prices gave way to a third day of selling this week.

The S&P 500 was down 0.4 percent at the end of trading, bringing its losses for the week to more than 6 percent. Bonds rallied, pushing the yield on the 10-year Treasury note to a record low for a second day, and the price of oil also fell.

Investors have been contending with the potential for the coronavirus outbreak to disrupt global trade and slow growth, and stock prices around the world have reflected concerns about the virus’s spread outside China. More than 80,000 people have been infected by the virus, which has killed more than 2,700.

Wednesday began with the S&P 500 rising more than 1.5 percent before giving up those gains. Market observers attributed the change in sentiment to comments from Germany’s health minister that the country was at the beginning of a coronavirus epidemic.