https://www.alojapan.com/1232616/nikkei-stock-index-tumbles-over-4-on-u-s-tariff-concern/ Nikkei stock index tumbles over 4% on U.S. tariff concern #Japan #JapanDonaldTrump #JapanEconomy #JapanFinancialMarkets #JapanInflation #JapanNews #JapanStockExchange #JapanU.s.Tariffs #news #Tokyo #TokyoNews #東京 #東京都 The Nikkei stock index briefly tumbled over 4 percent early Monday after plunges on Wall Street late last week on growing concern over a U.S. economic slowdown caused by President Donald Trump’s tariff policies. At 9:22 a.m., th…