Update 2 - 12:59:29 ET:

NASDAQ intends to re-open trading in all Tape C securities with a halt cross with a 5-minute quote only period starting at a time to be determined. NASDAQ will not be cancelling open orders on the book. Customers who wish to cancel their orders may do so and any customer who wishes to not participate in the re-opening should cancel their orders prior to the resumption of trading. Additionally, NASDAQ will clear all stale quotes from the UTP SIP prior to the commencement of trading.

Update - 12:40:40 ET:

NASDAQ Options Market (PHLX, NOM and BX Options) System Update: Due to the ongoing equity SIP issue NASDAQ (PHLX, NOM and BX Options)reccommends that firms route all open orders away. If firms need assistance with cancling orders please contact Market Operations at 215-496-1571.

First it was BATS self-helping against NYSE Arca, now it's Nasdaq's turn to break. Joking aside, AAPL dipped below $500 literally minutes before the NASDAQ broke. We joked earlier when we said any selling is enough to break the market. Now, we are not so sure...

CBOE joins the party and halts all Nasdaq interchange:

Meanwhile, overheard at the Goldman pits: "Market it zero, dude"