First off, it is not good thinking to assume malevolence before considering various plausible and reasonable non-malevolent explanations.

Second:  There are a few reasonable explanations why you might see many fewer coins on the order book than are being sold at around any specific price including: 1) Many exchanges allow for invisible orders, and Bitfinex is one of them, 2) some buyers will continue to put orders on the books, as they get sold into (and they don’t necessarily want to put a large buy order at one particular price and get all their orders sold into at once (then they would potentially run out of money if the price were to go lower) 3) of course, market orders do not show up on the books, and they can  be ongoingly propping the price at a particular price-point 4) and perhaps margin calls as last of the v8s mentioned.