Indeed the commission taken by the site is a thing in cases like this, the site took 2500 LTC of commission this week.
There options like what's done by bustabit to keep a commission of 50% without affecting the investors durings huge loss. The commission is taken only when the site is at its ATH profit.

Also there is new investors because their expected value is much higher when there is a low bankroll (they can have a higher %) and when there is a player wagering a lot, its theorically the best moment to invest.

I also did it after losing a lot first i added another investment yesterday. So  sometimes the new investors you see are in fact the old investors who added some additonal money.