We're having a problem today with a stale bid in the level II data for DHOXQ. The market maker BARD is showing a bid of 0.75 while there are asks as low as 0.45.
The Market Depth application as well as the data requested from the socket API have this problem. There's no indication that the bid is wrong.
Any recommendations for fixing the problem?

I've attached a screen capture of the Market Depth application and the raw Level II data is below.

Z,DHOXQ.PK,BMIC,0.35,1.5,2500,100,06:07:29.273,2015-01-20,52,06:07:29.273,T,T,T,
Z,DHOXQ.PK,BKRT,0.05,2.14,10000,100,08:13:08.984,2015-01-20,52,08:13:08.984,T,T,T,
Z,DHOXQ.PK,CANT,0.33,0.45,2800,2500,11:57:41.607,2015-01-20,52,11:57:41.607,T,T,T,
Z,DHOXQ.PK,MAXM,0.35,0.65,2500,1000,07:35:10.987,2015-01-20,52,07:35:10.987,T,T,T,
Z,DHOXQ.PK,ARCA,0.365,1.02,8200,300,14:30:15.006,2015-01-20,52,14:30:15.006,T,T,T,
Z,DHOXQ.PK,STXG,0.1,0.5399,5000,1000,10:29:35.612,2015-01-20,52,10:29:35.612,T,T,T,
Z,DHOXQ.PK,GUGS,0.35,1.25,2500,150,09:30:01.535,2015-01-20,52,09:30:01.535,T,T,T,
Z,DHOXQ.PK,STFL,0.0008,1.81,10000,100,08:00:01.629,2015-01-20,52,08:00:01.629,T,T,T,
Z,DHOXQ.PK,MITR,0.35,1.5,2500,100,08:03:11.992,2015-01-20,52,08:03:11.992,T,T,T,
Z,DHOXQ.PK,NITE,0.38,0.39,2500,13000,14:59:51.161,2015-01-20,52,14:59:51.161,T,T,T,
Z,DHOXQ.PK,PUMA,0.35,0.54,2500,1000,10:22:09.058,2015-01-20,52,10:22:09.058,T,T,T,
Z,DHOXQ.PK,INTL,0.,0.,0,0,99:99:99.000,2014-12-31,52,16:42:08.339,F,F,T,
Z,DHOXQ.PK,CDEL,0.35,0.4499,2500,3950,14:30:36.635,2015-01-20,52,14:30:36.635,T,T,T,
Z,DHOXQ.PK,ATDF,0.25,2.,2500,100,13:29:53.061,2015-01-20,52,13:29:53.061,T,T,T,
Z,DHOXQ.PK,BTIG,0.0101,1.4,10000,100,07:35:02.198,2015-01-20,52,07:35:02.198,T,T,T,
Z,DHOXQ.PK,VFIN,0.1,2.,5000,100,08:47:43.382,2015-01-20,52,08:47:43.382,T,T,T,
Z,DHOXQ.PK,ETRF,0.,1.,0,2900,99:99:99.000,2015-01-20,52,09:30:01.539,F,T,T,
Z,DHOXQ.PK,BARD,0.75,1.25,1000,100,05:32:19.173,2015-01-20,52,05:32:19.173,T,T,T,
Z,DHOXQ.PK,CSTI,0.35,0.68,2500,1000,14:30:13.476,2015-01-20,52,14:30:13.476,T,T,T,
Z,DHOXQ.PK,VNDM,0.1,1.02,5000,100,08:00:25.147,2015-01-20,52,08:00:25.147,T,T,T,

Hello,

It appears a bid did not get cleared just as you said. We have corrected this and it should look better now.

Tim

How often does this happen? I don't really care about this specific case, but if this sort of thing happens from time to time, I need to figure out a way to recognize it, and ignore the bad data. What do you recommend?

This is the first case of this I have seen reported in quite some time actually, but we are looking at this to see if we can identify the exception that caused this particular case.

I would think that some protection might be afforded by verifying the age of the bid or ask in relation to the ages of the surrounding bids and asks would be one way. In this case where it is the best bid or ask, as in this occurrence, you could compare the best bid and ask from level 2 to the best bid and ask from level one. If they are not equal then you could put in some logic there as well to consider deleting the potential bad bid or ask.

Ideally, we figure out what happened on our end and this is not something you need to deal with at all, and that is certainly always our goal and what we strive for. But, a little defense for when things go South somewhere in the cloud never hurts either.

Tim

This happened on the same symbol, with the same market maker on at least the 22nd as well (I didn't remember to check on the other days). So, this appears to be recurring.

Eric