Fears that uncertainty over trade tariffs will spark an economic downturn are causing investors to flee equities, in a major shift for Wall Street which had been fired-up by the prospect of President Donald Trump’s agenda. Stocks continued their steep decline on Monday, with the benchmark S&P 500 down 2% in mid-day trade and the Nasdaq Composite sliding more than 3%. The S&P 500 was down about 8% from its February 19 all-time high, nearing a 10% decline that would show a correction for the index. The tech-heavy Nasdaq ended down more than 10% from its December high last week….