Nanex ~ 28-Mar-2013 ~ Stock Quoting SurgeOn March 28, 2013 from 13:26:40 to 13:34:50, and then again from 13:57:25 to 14:05:50, the number of stocks quoted suddenly shot from around 1000 to over 3000. Close inspection shows all of the additional quotes came from Nasdaq, and were sent once per second on the second.
1. The first event. Showing percentage of quotes from each exchange.
Note the sudden jump in the gray shading - showing Nasdaq's percentage of quotes in all stocks.
2. The second event. Showing percentage of quotes from each exchange.
3. Close up of first event showing bids and asks color coded by exchange in stocks priced between 0 and $140.
4. Same as chart above, but showing bids and asks from Nasdaq in stocks priced between 0 and $140.