Yeah, when you "invest" you get own % (stake) of the bankroll. So when the bankroll grows or decreases, your stake stays the same. So if the bankroll doubled your investment would double. If the bankroll halved, your investment would halve. (Note: stakes are readjusted when people invest or divest, so you only make money when the bankroll gains money from gamblers)
but when the bankroll grows or decreases my stake in the bankroll also changes, so you are telling me that if I had invested when the bankroll was at 100 btc profit and now it is 2.2k btc profit I would have 22x my investment?