NEW YORK (Reuters) - The cost for Wall Street to fund dollar-based trades rose on Friday to the highest in nearly three months as Britain's vote to leave the European Union stunned investors, causing reluctance to lend as global stock markets plunged.The interest rate in the $3.8 trillion repurchase agreement market, where traders raise short-term cash from investors by pledging securities as collateral, was last bid at 0.80 percent, which was the highest since 0.85 percent on March 31, according to ICAP.The overnight repo rate was quoted above 1 percent earlier Friday before retreating.On Thursday before the surprise outcome of...