Quote from MechTrade:
What does this really mean to index spread traders @ IB?
Does this access to SPX mm's via IB's tradedesk make trading the SPX any better or worse than trading NDX or RUT in terms of being able to judge accurate bid/ask spreads for putting on trades with the best R/R ratios?
Even with NDX & RUT, I've found that mid prices need to be 'probed' with several small orders at various levels around the mid to find the sweet spot for executions. And by fishing you can often get better than quoted mid-price executions.
You are correct that the markets need to be probed, b/c the mid-point of the displayed market is not always the true fair value. The best way to do that is to get a firm quote from the pit so you have information prior to exposing an order, rather than giving this info to the market makers.
For IB clients trading SPX in size of at least 100 contracts per leg, we can typically get .30-.50 wide markets for significant size, compared to the ~$2 wide displayed market.
Please contact me via private message w/ any questions. Thanks.