The market centralizes naturally on these traders desks. We believe it is more effective to rely on this simple natural force than to try to establish complicated rules and interconnections to try to solve fragmentation. Rule 390 is anti-competitive. It has long outlived its usefulness. Liquidity is encouraged by price and time priority, which encourages limit orders to thicken the quote.
Disclosure is the best cure for many ills, including potential problems with internalization.
Similarly, all markets' BBO and executions should continue to be promptly distributed. Let market innovation deal with any problems of fragmentation. Thank you for the opportunity to comment on these vital issues.