goodJohn, it means beer is pulling us all a leg.
PPHM on L3 means you see extra depth and hidden volume as well as ECN's book depth etc. You see ALL the market Maker too (there are many on NASDAQ).
So Knight Capital, an ECN, is listed at L3 with the symbol BRUT and not with its NASDAQ ticker symbol NITE where it is listed as a company just as is PPHM.
An ECN holds its own book and participates with its Level 1 in the National Best Bid/Ask (which is what you see and call the L1 Bid and Ask).
If Night Capitals customers would be buying big then in Level 3 where you also see their book detail behind their L1 you would see BRUT at the top of the stack for PPHM and you would see bigger volume then for the other ECN's and for NASDAQ direct itself.
But it isn't the case, I assure you and if it was it would mean nothing because an ECN is just an execution channel with a book attached to it allowing them to short cut a trade provided they shoot it in NASDAQ's T&S and provided they don't cross the market and follow the SEC up-tick rules etc.
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