An electronic board displays the Nikkei Stock Average in Tokyo on Monday. (Kazuhiro Nogi/AFP/Getty Images)

Japan’s exchange operator briefly called a halt to trading in Nikkei stock futures on Monday morning because of a sharp fall triggered by President Trump’s tariffs.

The “circuit breaker” system calls for a 10-minute pause in trading when the widely traded Nikkei 225 futures product is poised to rise or fall more than 8%. The product represents a bet on the direction of the Nikkei Stock Average of 225 issues. The circuit breaker kicked in at 8:45 a.m. Tokyo time for the Nikkei 225 and several other futures contracts, and it ended 10 minutes later. Spot trading—direct buying and selling of shares on the Tokyo Stock Exchange—wasn’t affected. The spot Nikkei 225 index was down about 6% Monday morning, recovering somewhat after earlier falling nearly 9%.