Fear is back in the market.

Investors are worried about slower economic growth in China, a gloomier outlook for U.S. corporate profits and an end to easy-money policies in the United States and Europe. They’re also fretting over country-specific troubles around the world — from economic mismanagement in Argentina to political instability in Turkey.

Those fears converged this week to start a two-day rout in global markets that was capped by a 318-point drop in the Dow Jones industrial average Friday. It was the blue-chip index’s worst day since June. The Dow plunged almost 500 points over the two days.

The Dow finished down 2 percent at 15,879 Friday. The Standard & Poor’s 500 index fell 38 points, or 2.1 percent, to 1,790. The Nasdaq composite fell 90 points, or 2.2 percent, to 4,128.

As investors shunned risk, small-company stocks fell even more than the rest of the market, and bond prices rose.

Despite the sell-off, U.S. stocks remain near all-time highs after surging 30 percent last year. The S&P 500 is 3 percent below its record high of 1,848 on Jan. 15.

U.S. stocks have not endured a correction — a drop of 10 percent or more over time — since October 2011.

The turbulence coincides with a global economic shift: China and other emerging-market economies appear to be running into trouble just as the developed economies of the United States and Europe finally show signs of renewed strength nearly five years after the end of the Great Recession.

The trouble began Thursday after a January survey showed a drop in Chinese manufacturing activity. Days earlier, China reported its economic growth last year matched 2012 for the slowest pace since 1999.

“It is interesting how even a mild tremor in China’s growth causes such anxiety around the world,” said Eswar Prasad, professor of trade policy at Cornell University.

In Asia, Japan’s Nikkei 225 slipped 1.9 percent Friday to close at 15,391.56; Hong Kong’s Hang Seng shed 1.2 percent to 22,450.06; and Seoul’s Kospi dropped 0.4 percent to 1,940.56.