The short story:
The rules adopted today update and expand the content of NMS market data to include:
(1) information about orders in share amounts smaller than the current round lot size (e.g., 100 shares);
(2) information about certain orders that are outside of an exchange’s best bid and best offer (i.e., certain depth of book data); and
(3) information about orders that are participating in opening, closing, and other auctions.
Also:
Competing consolidators, rather than the existing exclusive SIPs, will collect, consolidate, and disseminate certain NMS information.
Effective in 60 days, but a phased transition plan begins in 2021 to avoid chaos.
