Quote from Surprise:
Does the ES or the SP500 pit traded futures contract has any influence over the SP500 cash index ? What i know is the opposite , the futures contracts track the cash index ...
Either you phrased this incorrectly, or it is a very silly question.
What do you think the index arbs do? Sometimes the pit traded futures led, other times the cash.
If there is a wide enough spread (determined by time till expiration and interest rates which arb can borrow money) and cash is higher, sell programs kick in.
If there is a wide enough spread (determined by time till expiration and interest rates which arb can borrow money) and cash is lower, buy programs kick in.
Indexarb.com may be helpful
Is this what you meant? That's what makes them correleated obviously.

