TL:DR - Polo is a ponzi exchange, you're an idiot if you're still trading there.
if it was it would effect a lot of coins and prices, it is still a leading volume trader for some coins, i don't use it much now, i prefer other exchanges, but if it is a ponzi it would fuck the system up.
Its not going to fuck the system up its those users who stores tokens there who will be fucked up. But I doubt they'd turned crypsy soon. Their exchange justbearn so much a day, they would rather fix the problem than going to be replaced by bittrex. Its a disappointment if yobit rules in the future.