Japan's Nikkei tumbled 20% in 2006 after the BOJ stopped asset purchases, says SocGen. Leading up to end of that QE episode, the index had gained 62%. When the Fed's initial QE effort ended in 2010, the S&P 500 was 16% lower two months later. The ending of QE2 brought with it a 17% one-month decline.
Taking the opposite tack, RBC's Jonathan Golub says the Fed remains "uber-accommodative" and puts his S&P 500 price target at 1,950 for the end of 2014.