For months investors piled into stocks because of "liquidity". Now they are fleeing because of "Greece". In truth investors are always chasing the herd and trying to rationalize it. What they are actually doing is following a primal instinct and trying to feel good intellectualy about it.
If the market were ready to correct at the time the Dubai news hit, the decline would have been blamed on Dubai. If the market were ready to correct in early January when we had the weak unemployment report, "unemployment" will have been blamed. You get the picture.
I am not saying this will not continue as the market is overvalued and we saw a pile in of epic proportions. I am just saying this has less to do with Greece than most believe.