The chart below shows message rates for UQDF which carries quotes for Nasdaq stocks.
You can see the odd cycling behavior that lasts for exaclty 1 second and is followed
by a surge.
This was due to the feed being overloaded.
One result of that overload was trades appearing before quotes, like in MSFT.
UQDF is sent on 6 multicast lines which are grouped by the symbols first character
as follows:
Line 1: A-B
Line 2: C-D
Line 3: E-I
Line 4: J-N
Line 5: O-R
Line 6: S-Z
UQDF overload on October 21, 2011
UQDF overload on June 24, 2011
Close-up of UQDF overload on June 24, 2011
UQDF overload on July 1, 2011
UQDF overload on July 5, 2011
UQDF overload on July 13, 2011
UQDF overload on October 24, 2011
Nanex
