Global stocks slump, safe-haven assets soar as Brexit risk weighs

By Dion Rabouin NEW YORK (Reuters) - Fears of instability in the European Union and prolonged global stagnation sent stock markets sharply lower on Wednesday as Britain's pound sank below $1.30 for the first time in more than three decades and U.S. Treasury yields again hit historic lows. After last week's stock rally when investors bought riskier assets in the days after Britain's decision to leave the European Union, the implications of another round of financial losses, interest rate cuts and