well, i have no doubt about it.
but we have no evidence for proofing it.
that the problem , even big exchange like binance can do that, but we clearly have no evidence.
i will being neutral on this cases , although we know average IEO on binance have a quite profit for investor,but that did not rule out there have a manipulation inside.
i just have speculate,probably it will be happened if some investor investing with a huge amount of money to some project and the exchange take a part on IEO or even the team it self, and well,we see massive dump after token sale, even didn't touch ROI.