Jeffrey Gundlach, the widely followed investor who runs DoubleLine Capital, foresees a “global growth scare” between now and the end of the summer, triggered by a presidential nomination of Donald Trump. “That is where I see the vulnerabilities,” Gundlach said in a telephone interview on Monday. Trump’s protectionist policies could mean negative global growth, Gundlach warned. “As he gets the nomination, the markets and investors are going to worry about it more. You will see a downgrading of global growth based on geopolitical risks. You must factor this into your risk-management.”