Nikkei falls about 4% as tariffs take effect

The Nikkei fell today, ending the session down about 4% amid a broad sell-off as traders assess concerns about a potential economic slowdown amid an escalating trade war between the United States and China.

The Nikkei fell 3.9% to close at 31,714.03, while the broader Topix index fell 3.4% to 2,349.33.

The Nikkei has been markedly volatile this week, closing up 6% on Tuesday after tumbling 7.8% on Monday to its lowest level in a year and a half.