sp500 index options electronic auction mechanism

[JSOP]

From the retail trader perspective, it's only 2 option orders. From an exchange perspective, it's a single trading instrument, meaning that when the spread trades, the 2 legs have to trade. One leg cannot trade while the other does. The spread print has its own price, from which leg prices are derived.
Also, there are US option exchanges where COB and regular leg book can interact. And since there are rules for auction to respect, allowing auctions on Complex Order is not that simple.

One of the goals of Brokers is to present US option trading as one market by unifying as much as possible the way clients can trade. But in fact, there are 16 different option exchanges, with different trading rules and market models. One exchange can support one feature, while another one doesn't, or they do it, but differently. Generally speaking, retail clients don't see that.

Since 100% of the SPX option trades are executed on CBOE so it's CBOE's rules that's going to impact the SPX option trades. What other exchanges do are kind of irrelevant here. So it's quite perplexing that this press release didn't mention anything about whether this new auction features are going to be applied to mullti-leg option trades as well if you say for exchanges simultaneous multi-leg option trades are treated as one instrument with one price instead of two trades with two prices.

 

[JSOP]

Auction mechanisms were originally developed to allow crosses (internalization) in the US option market. The incentive given to the regulators were to give the opportunity to retail client to get price improvement on their orders.

For an auction to start, it needs 2 things (simple example cause it may be more complex):
1) A retail order (called Public Customer order)
2) A market participant willing to cross (internalize) that order, meaning willing to take the opposite side of the retail order.

Then an auction is launched for other market participants to submit orders to improve the original retail order. Any remaining quantity left that has not been improved is traded against the auction participant who submit the auction.

There are mechanisms that exists allowing market participant to send their order flow to other participant in order for them to start an auction.

Maybe a link with more details would be helpful:
https://boxoptions.com/about/price-improvement/

Btw, this is the implementation at one exchange. Many other exchanges also support auctions, and they have their own set of rules.

Ok so this looks like it either competes with the MM's that pay for order flows like Citadel if you are a retail trader that trades with a broker that happens not to receive payment for order flows (like IB according to what they claim) or allows the MM's that pay for order flows to turn around and make an even bigger spread by going onto the opposite side and initiate an auction as a "customer order" to get price improvement. The retail traders according to what you posted as the possible auction mechanism will get even more jipped by staying with a broker like RH that accepts payments for order flow because they will never be able to participate directly in the market as a "customer order" and will always have their orders internalized by the MM's.

Given how prevalent payment for orderflows is, this auction feature is really benefitting MM's more than the retail traders UNLESS the payment for orderflow-accepting brokers are willing to offer two types of trading platform to the retail traders, one with the status-quo with orders still internalized by the MM's that paid for order flows but zero or low commissions and another with guaranteed direct transmission of their orders to the exchanges bypassing the MM's that paid for order flows to participate in this new auction feature but with a commission or higher commissions and let retail traders choose which platform they want to be on.

 

[ajacobson]

No public payment in SPX and spreads most likely will be excluded, because they're not price protected on their individual legs. If you want more details there is a 30+ page detailed expiation on the sight.

 

[DiceAreCast]

Thank you

Ok so this looks like it either competes with the MM's that pay for order flows like Citadel if you are a retail trader that trades with a broker that happens not to receive payment for order flows (like IB according to what they claim) or allows the MM's that pay for order flows to turn around and make an even bigger spread by going onto the opposite side and initiate an auction as a "customer order" to get price improvement. The retail traders according to what you posted as the possible auction mechanism will get even more jipped by staying with a broker like RH that accepts payments for order flow because they will never be able to participate directly in the market as a "customer order" and will always have their orders internalized by the MM's.

Given how prevalent payment for orderflows is, this auction feature is really benefitting MM's more than the retail traders UNLESS the payment for orderflow-accepting brokers are willing to offer two types of trading platform to the retail traders, one with the status-quo with orders still internalized by the MM's that paid for order flows but zero or low commissions and another with guaranteed direct transmission of their orders to the exchanges bypassing the MM's that paid for order flows to participate in this new auction feature but with a commission or higher commissions and let retail traders choose which platform they want to be on.

 

[DiceAreCast]

And that should tell you for messed up the current system is. 30 pages for one aspect of order matching tells it all.

No public payment in SPX and spreads most likely will be excluded, because they're not price protected on their individual legs. If you want more details there is a 30+ page detailed expiation on the sight.