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
Especially since bfxdata is a third party site.
Here's a screenshot of what you are looking for: https://i.imgur.com/SvSFYMK.png
edit1: I also added that graph to the post.
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