 The over 1 drop in the SP 500 yesterday saw a daily close below its 50.0 Fib retracement level of the swing higher from October, seen at 3,796. That has been a level limiting further downside in the past week, before we headed into the Christmas break.But as we move towards the turn of the year, sellers are taking charge and pushing the agenda, in search of the next downside leg for stocks. 