NEW YORK — Escalating protests in Egypt jarred world financial markets on Friday. Stocks fell while the dollar, Treasurys and gold rose as investors sought to reduce their exposure to risk.

“The safety trade is back,” said Jeffrey Frankel, president of broker Stuart Frankel & Co. “Gold is up. Oil is up. Anything related to overseas is getting hit.”

Prices of Treasury bonds, considered one of the safest assets, rose sharply. The yield on the benchmark 10-year Treasury note fell to 3.33 percent from 3.38 percent late Thursday. Bond yields fall when their prices rise.

The dollar rose 0.5 percent against an index of six other currencies as investors sought safety. Gold rose 1.7 percent to settle at $1,340.70 and crude oil rose 4.3 percent to $89.34 a barrel.

The MSCI World Market index, the broadest measure of the world’s stock markets, slumped 1.4 percent.

“Traders are watching this flare-up in the Middle East and using it as a reason to take profits,” said Doug Godine, managing director at Signal Hill, an investment bank.

Of the 30 large-company stocks that make up the Dow Jones industrial average, 28 fell. The two exceptions, Procter & Gamble and DuPont, were flat.

The Dow fell 166.13 points, or 1.4 percent, to close at 11,823.70. That’s the worst one-day drop since Nov. 16.

The Dow lost 0.4 percent for the week after eight straight weeks of gains.

The Standard & Poor’s 500 index fell 23.20, or 1.8 percent, to 1,276.34. All 10 company groups within the S&P index fell. The S&P fell 0.5 percent for the week.

The Nasdaq composite fell 68.39, or 2.5 percent, to 2,686.89. Because of technical problems, the index was not updated nearly an hour after the market opened. The Nasdaq lost 0.1 percent for the week.

Disappointing earnings reports also rattled investors, said Brian Wenzinger, a portfolio manager at Aronson Johnson Ortiz in Philadelphia.

“Some companies, like Apple, are doing well, but the bulk are not being too optimistic,” Wenzinger said.

Amazon.com Inc. fell 7 percent after reporting that higher costs cut down its profit margins.

Microsoft Corp. lost 4 percent after it said that the profitability of its Windows division was falling.