The Dow Jones industrial average rose on Thursday, but the S&P 500 and Nasdaq composite closed lower as investors assessed the possibility of a trade war.
The 30-stock index rose 115.54 points to close at 24,873.66, with UnitedHealth contributing the most to the gains. Earlier in the session, the Dow rose nearly 300 points. Boeing, which has struggled throughout the week, fell 0.1 percent in choppy trade Thursday.
"Boeing got hit three days in a row earlier in the week because people felt that was a way the Chinese and others could" retaliate, said Art Cashin, director of floor operations for UBS, on CNBC's "Squawk Alley."
"You're going to get that kind of ebb and flow," Cashin said. "I would continue to keep my eye on Boeing. I think it's going to be the critical factor in the Dow."
The S&P 500 fell 0.1 percent to 2,747.33, with losses in materials offsetting a 0.3 percent gain in industrials. The Nasdaq composite pulled back 0.2 percent to 7,481.74.
The White House is thinking about implementing tariffs on at least $30 billion of Chinese imports as part of a package of anti-China measures, the Wall Street Journal reported. Reuters also reported Tuesday that President Donald Trump may impose tariffs on $60 billion of Chinese goods.
Investors worry that other countries could retaliate by implementing their own tariffs on U.S.-made goods and sparking a trade war. This would hurt companies who do business overseas, especially large multinationals like Boeing.