Nanex Research

Nanex ~ 21-Mar-2014 ~ A Record Setter

On March 21, 2014, at 15:45:00, a new record was set for most trades in 1 second in NMS stocks (NYSE, NY-ARCA, NY-MKT and Nasdaq listed stocks and ETFs - approximately 8,000 symbols). The 3rd and 4th most active seconds were also set, at 15:50:00 and 15:55:00 respectively. The 2nd most active second was set at 10:00:00 on September 1, 2011.

See also March Expiration Games and 1/10th of a Second in QQQ from the same day.

1. NMS 1-second peak Trades per Second for each minute of the regular trading session (9:30 - 16:00).
Each day is drawn as a line, color-coded by age: from violet (oldest) to red (most recent).  




If we take a close look at the 15:45 peak, we find something all to common: severe network overload, saturation and delay. The 15:45 peak came mostly from CTA - the SIP carrying trades for NYSE, NY-MKT and NY_ARCA listed issues. Closer inspection reveals that the SIP carrying quotes for these stocks (CQS) was also overloaded.

The CQS/CTA SIPs send quotes/trades for all NYSE, NY-MKT and NY-ARCA listed symbols over 12 multicast lines. Each multicast line carries quotes for a certain range of symbols alphabetically. For example, symbols beginning with letters A and B might be transmitted on line1, C and D on line 2 and so forth.

2. CQS ~ Quote for NYSE, NY-MKT, NY-ARCA listed stocks at 15:45:00.
Note how the multicast lines hit a wall and rotate, taking turns outputting data. The number of crossed/locked NBBO's (bottom panel) skyrockets.


3. CTA ~ Trades for NYSE, NY-MKT, NY-ARCA listed stocks at 15:45:00.
Solid system overload in trades too.


4. CTA at 15:55:00.
Same overload pattern.



The UQDF/UTDF SIPs send quotes/trades for all Nasdaq listed symbols over 6 multicast lines. Each multicast line carries quotes for a certain range of symbols alphabetically. For example, symbols beginning with letters A and B might be transmitted on line1, C and D on line 2 and so forth. Since this is a completely different system, it handles queuing a little different than CQS/CTA. We've covered examples of overload in UQDF before.

5. UQDF ~ Quotes for Nasdaq listed stocks at 15:50:00.
The oscillation pattern is indicative when UQDF/UTDF are overloaded. The number of crossed/locked NBBO's (bottom panel) skyrockets.


6. UTDF ~ Trades for Nasdaq listed stocks at 15:50:00.
Same oscillation pattern shown by quotes above.



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