As smart as not supporting negative oil pricing.
Not only did they not know it could not go negative.
They also had very low margin requirements on CL at the time.
The CME dropped the ball on this, big time.
Cant blame CME, IB are the ones who claim they extra conservative when it comes to risk and will go well over CME requirements at the drop of a hat.
We, myself and other posters, pointed out weeks before the oil price crash that CL margin were so low while ES was so high. We posted this on ET many times.
If we could see it why couldnt the risk managers at IB?