Business ReportBEFORE THE BELL: Global markets roiled by trade war fears as US and China do battle over tariffs SHARE ON: James Bowler, contributor, Friday, Mar. 23rd, 2018As the US and China begin battling each other with import tariffs, investors fearing a trade war are causing global market volatility. The Nikkei plummeted four per cent in overnight trading as it fell close to a six-month low at 20,617. Donald Trump is threatening over $60 billion in tariffs and the Chinese have responded with three billion on US imports.Gold has jumped to its highest since a market bloodbath in February, up one per cent to 1,342. The precious metal is often used as a safe haven for fearful investors.The price of crude continues to climb, up to 64.51 a barrel.The Loonie is up to 77.34 cents US.Traders are watching medical marijuana producer stocks after the legalization bill passed a second Senate reading in Canada. Analysts say this could boost shares across the board.