The floodgates are open for the markets’ largest emerging market stock ETFs after the Fed opts to keep its monthly bond-buying stimulus intact.

The $50 billion Vanguard FTSE Emerging Markets and the $40 billion iShares MSCI Emerging Markets jump more than 2% to their highest levels since May. Left for dead by some investors earlier this year, traders say it's the big post-FOMC slide in the dollar that's helping drive up EM stocks.