US stocks have closed slightly lower, regrouping from early losses following attacks on the airport and a rush-hour metro train in Brussels.
Islamic State claimed responsibility for suicide bomb attacks in the Belgian capital that killed at least 30 people, with police hunting a suspect who fled the air terminal.
Travel sector stocks, including airlines and hotels, were among the hardest-hit, although equities managed to recover from sharp losses and bonds and gold eased from their early highs.
On Wall Street, the NYSEArca airline index lost 0.9 percent and was on track for its first decline in five sessions.
Cruise ship operators Royal Caribbean, down 2.9 percent and Carnival Corp, down 2.1 percent, were among the worst performers on the S&P 500.
Those declines were offset by gains in Apple, up 0.8 percent to US$106.72 and a 0.9 percent gain in the healthcare sector.
"The news obviously has been dominated by what has gone on in Brussels, but experience tells us not only is it the morally right thing to do to basically not overreact, it also turns out to be the most profitable thing to do," said David Kelly, chief global strategist at JPMorgan Funds in New York.
"The objective of terrorists is to disrupt and, to the extent that they can, do horrible things but at least we have the small victory that they have not disrupted global financial markets today."
The Dow Jones industrial average close 41.3 points, or 0.23 percent lower, to 17,582.57, the S&P 500 lost 1.8 points, or 0.09 percent, to 2,049.8 and the Nasdaq Composite added 12.79 points, or 0.27 percent, to 4,821.66. In Europe, the STOXX Europe 600 Travel & Leisure index was down 1.8 percent. Shares in major European airlines like Ryanair and Air France-KLM also fell.
Volume is expected to continue to diminish ahead of the Easter holiday, and investors were beginning to think about cashing in on a steep rally in stocks over the last few weeks.
Gold was up 0.31 percent at US$1,248.10 an ounce after hitting a high of US$1.259.60 earlier.
Benchmark US 10-year notes were last down 6/32 in price to yield 1.9403 percent after falling as low as 1.879 percent as Chicago's Federal Reserve president struck a bullish tone on the US economy.