Anyway, how on Earth are these leveraged longs holding on for these periods of time while paying these sky-high interest rates? Especially considering interest rates for USD are at record lows in the real world ... It just makes zero chance. I would not be surprised if something shady is going on.
Just look at the charts - as long as there are swings like this, 0.2%/day interest is pocket change. Also consider that other exchanges charge more for a single trade (often from both sides), not just per day. If you trade one single time less you already have saved the swap fees...