FYI, we haven't charged this insurance fee since late July - while we were on free trading in late July through August, we greatly simplified the fee system for when it turned back on in September. We simply do flat trading fees (mostly maker/taker 0/0.05%). We found this to be much easier for everyone to understand and to compare with other platforms.

That said, charging a funding fee makes sense on a margined platform where there is risk of loss, and that's why we did it in the first place. We found in the end that the confusion was not worthwhile, but it's a perfectly legitimate fee structure.