Here's the daily chart. The market is bouncing off the 200-day SMA. While these late day advances add to the excitement, they do little to convince me the market is in a good place.
Yesterdays' rally appears to be the result of a "fat-thumbed trader" (a great term from Barry over at the Big Picture Blog):
"Error at the bell last night (clarification): This error at the bell last night really did contribute to the rally. Bottom line is that one of our competitors inadvertently sold 5346 too many of the SPX Sep 1450 calls and needed to cover them in a hurry. At the time the mkt was down 1% on the day.
In covering, it is likely the crowd front ran the order, exaggerating the move.
Once the move got going, the variance hedging phenomenon kicked in. Most dealers place MOC (Mark on Close) orders to hedge their daily delta risk.
If this theory holds, then they would have put in large sell orders yesterday MOC at around 3:40PM. Once the mkt started to run, their delta position would've changed from net long to net short and they would have needed to buy that much more SPX exposure into the bell. Our index trading desk predicts that for every 2 pt move up in the SPU, dealers needed to buy approx 500MM notional in delta.
With liquidity being lousy right now, that created the violent move."