Quote from gmst:
Anyways before our troll emg posts more garbage on this thread and destroys it, here is my theory:
Today's size was different from the size of few months ago. Few months ago, that size was at a key level (150 in spy) and its presence could be due to hedging some one-touch option, or spy-ES arbitrage or someone wanting to buy at 150 - I don't know. But the point is that size got filled slowly. I saw 8000 contracts getting filled.
Today on the other hand, when price came back after making morning low, the big size at 1629 level vanished. So, today was definitely not like last time.
My final conclusion is that huge displayed size at least early in the morning of today at least shows some institutional selling interest at this level. No retail trader has the margin to show 11000 ES size and no small trading firm will have the guts to put so much size on display (even if they have the risk limit). No HFT firm would put that kind of size in ES. So, the market participant behind it has to be some old fashioned fund or bank trading desk. This is why I think there is some institutional selling interest around this level. So over the next few days we might see S&P correct a bit, maybe even fill the gap around 1595 or so.