False fills for limit orders, a big problem

Hi C2 admin,

Recently there has been a huge increase in false limit order fills, where the market price does’t cross the limit price and the order is triggered anyway.

This is creating a lot of disruption on a lot of systems, causing confusion and loss of money.

I don’t understand what the problem is but I think C2 should raise the fix priority to max since it is a very important problem to be fixed.

A little feedback to C2 customers would also be appreciated.

Thank you.

Hi, Dude:

Yes - this has been a sudden and surprising issue. Basically one of our broker partners’ quote-feeds started going completely bat-shit crazy about 2 days ago. Things had been fine before that. But something changed.

We have reported the problem to the broker and we are trying our best to work with this broker to help it figure out why it is reporting prices that haven’t actually happened. (This in turn has caused problem at the C2 side, which you noted.)

About 20 minutes ago we gave up waiting for this broker to fix the issue. We introduced an emergency patch on our servers which will ignore the really insane bad quotes from this specific broker. There still may be limited numbers of cases where the broker reports an erroneous quote that is within the realm of the possible, but the patch we put in place should solve most of the problem.

We’ll continue to work to resolve this. If things can’t be solved on the broker’s side, we’ll need to shut the broker off from C2, at least temporarily, but this will cause a lot of disruption to a lot of customers, and so we’d rather work closely with the broker to help them solve it.

Anyway, I’m sorry I haven’t posted more info on this before now. We’ve been racing to get to the bottom of it and solve the problem. It looks like our just-implemented patch (literally 20 minutes before posting this message) may have largely resolved it. Fingers crossed.

Francis and I will keep our eyes open and continue to monitor.


Thanks for the feedback, I understand now.

Those guys at the broker need to do their job so keep pushing them.

I hope you stabilize it soon, good luck.

Your patch isn’t working for me. Yesterday (Friday) three incorrect positions were opened. I think that makes seven in the last week, most of which were losers. I advise autotraders of Rainier to use extreme caution until C2 fixes this.



The fix we implemented checks if a fill report by a broker is within the realm of possibility. That is the catch, of course – what does the “realm of possibility” mean? We set a threshold of reasonableness; the incident you are describing happened because a fill report was within this range that looked reasonable.

The broker has promised to get to the bottom of this, and we would prefer not to shut down C2 access to a well-regarded partner broker used by many C2 customers. I hope we’ll be able to announce resolution on this very soon. We are working closely with the broker to resolve this. Please try to hang in there.