From Trader Mike

Wednesday capped one of the strongest runs to a new high we've ever seen in the S&P 500.  With Wednesday gaining more than 1%, and being the largest gain in the past three weeks, with no losses greater than -0.35%, there have been only 6 precedents since 1928.  Over the next 2-3 weeks, all of them pulled back, but none of them marked a major high.  The dates were 9/13/55, 1/30/61, 3/15/71, 12/18/92, 10/14/93 and 10/4/96.