https://www.sec.gov/spotlight/emsac/memo-rule-611-regulation-nms.pdf
A trade-through is defined as the purchase or sale of an “NMS stock” during “regular trading
hours” (9:30 a.m. to 4:00 p.m. ET), either as agent or principal, at a price that is lower than a
protected bid or higher than a protected offer. An NMS stock generally means any exchange-listed security (other than listed options) for which consolidated market data is disseminated.
I read through your link and I'm a little confused. Sorry if these answers should be obvious. I am really trying to nail down the specifics of order execution. Any clarification you give is appreciated. Thanks @Robert Morse!
- So in extended hours sessions, limit orders are NOT protected against trade-throughs?
- In regular session: Do attributes (hidden vs. lit / smart vs. direct routed) affect the protection rights of a limit order?
- How come trade throughs still happen if they are illegal (during RTH sessions assuming all requirements met)?
