Datek had told me that stops on NASDAQ stocks are activated when NBBO reaches the stop activation price. One question: what if the NBBO on Time/Sales never reaches the stop activation price, but there is an actual transaction done at the activation price. For example, if I'm long at 20.10 and stop is at 20.00; if the lowest best bid shown on Time/Sales is only 20.01, but there is an actual transaction done at 20.00; is the stop supposed to be activated, or not activated because the lowest bid never reached 20.00? Also, do the brokers activate stop on temporary odd bid/ask, that ever shows up on Time/Sale? For example, if the stop on a long position is at 20.05, and the bids are pretty much 20.15 or above, but there is some oddball bid at 20.04, would the stop execute? What about on NYSE, where stops are executed based on last transactions, do the brokers activate the stops on single odd transaction for 100 shares that might be 30 cents away from all other transactions that occurred around the same time?
About datek, i had used stop orders and they were activated when the price reached best bid/ask on Level II - no trade was necessary.