someone with too much money
buy otc => dump on exchanges
easy manipulation
Isn't buying otc more expensive? Why would anyone do that just to keep the exchange rate low? What's the gain?
Correct, OTC is more expensive.
People usually buy from the exchanges to sell OTC.
Or, they find a OTC miner that can sell below bitstamp then they turn around and sell to retail buyers OTC (rather than making a tiny % selling on exchange).