Since your latest UI update a few weeks ago your site seems to be leaking memory. A lot of it, especially on the "Margin trading" tab and a bit less so on the Stats page (in fact, almost every single page does so but these are the worst ones). That is to say if I keep the Margin tab open for a mere 24hrs it is consuming about 1.2+ GB of RAM, almost 15x as much as when it was freshly loaded. The Stats page within the same timespan is using about 4-5x as much as when it was freshly loaded.

I tested in the latest Chrome stable but I'm pretty sure it happens in any other browser. I tried debugging it for a bit, seems as if you're not re-using DOM-nodes within your AJAX-"framework" (or whatever kind of messy hairball you seem to be compiling in there). It's constantly adding new nodes without cleaning up/reusing them afterwards. The DOM-node count always seems to go up after a call to update_tickrates() but im just too lazy to analyze your 80.000+ lines of (re-formatted) JS Code. 80k lines for a site as, well, still quite simple as BFX just seems like an awkward amount of over-engineering to say the least. It would be nice to have a responsive site again without having to kill and reload tabs every other day.

Other than that, your UI redesign looks really nice