The latest volley between the United States and China has mostly involved advanced manufacturing technologies, a dispute that parallels the countries’ fight over steel and aluminum. The overall value of the duties at issue is small given that total trade between the two countries amounts to around $650 billion a year. But economists and investors say the tensions could ratchet up quickly, and that the tariffs could become more punishing.

The growing tensions have helped erode many of the stock market gains that Mr. Trump had touted since taking office. The Dow Jones industrial average has recently slipped to its lowest level of the year, despite generally positive economic growth around the world and tax legislation in the United States that has helped bolster corporate profits.

The trade dispute also reverberated in commodities markets Wednesday. Cotton prices fell 2.9 percent, and soybean prices dropped 2.2 percent. Corn prices declined by 1.9 percent.

Analysts at Goldman Sachs said China’s imposition of tariffs on soybeans, an agricultural staple in Midwestern swing states, was a sign of worsening friction between Washington and Beijing.

“We view the inclusion of soybeans in today’s announcement as political in nature and reflective of the escalation of the trade dispute with the United States,” Goldman Sachs commodities analysts said in a note to clients.

Despite the volatility in stock trading, there was little sign of a rush to the safety of United States Treasury bonds. Instead of falling sharply — a signal of a panicky market — yields on 10-year Treasury notes were largely stable, finishing the day at 2.78 percent.