[runeks]

It fell from $29M to $24M: http://www.bfxdata.com/swaphistory/totals.php

But that drop doesn't happen at the same time as the big drop on Bitfinex, as far as I can see. I assume all times are UTC, unless otherwise stated.

The drop in total sum of USD swaps fell from 2014-08-14T07:30 to 2014-08-14T08:30, but the drop on Bitfinex happened around 2014-08-14T10:00

[mattodell]

The thing is that Bitfinex only reports their leveraged volume every hour so you can't really pinpoint the margin calls.

Especially since bfxdata is a third party site.