Stocks turned mixed by late morning Tuesday as investor fear over what impact a terrorist attack in Brussels might have on markets faded.
The S&P 500 was down 0.09%, the Dow Jones Industrial Average declined 0.19%, and the Nasdaq gained 0.09%.
"It is all to do with the events in Brussels ... but the reaction is muted, which also shows that after all the terrorist attacks we have seen, markets have learned to live with these kind of things," Rabobank eurozone economist Emile Cardon told Reuters.
At least 26 people have been confirmed dead and many more injured after suicide bombers triggered explosions at the airport in Brussels and a metro station, according to reports. The attacks are believed to be in connection with the arrest earlier this week of the main suspect in the Paris terrorist attacks in November. The situation is still developing.
Travel stocks, including airlines and online-booking sites, were hit hardest on the reports. Airlines United Continental (UAL) , Delta Air Lines (DAL) , American Airlines (AAL) and Southwest (LUV) were all lower. Priceline (PCLN) and Expedia (EXPE) were also in decline.
"Investors should ... be braced and positioned for more stock market volatility if in fact the terror attacks continue or larger conflicts begin," Bill Stone, investment strategist at PNC, wrote in a note. "This positioning includes being in an asset allocation that both matches your objectives and ability to withstand price swings."