I wasn't thinking about some fake price they set on their own exchange, but actions that could tank the market, which I understand Binance alone makes up 30% of.

Crypto at it's current price has a market cap around $2.6T. Obviously the liquidity is questionable, and since crypto isn't connected to any mention worthy real economic activity, a change in sentiment can quickly crash the price and liquidate leveraged positions.

While that's of course true for other assets also, crypto not being connected to production of real value, combined with the comparative lack of regulation, makes it much easier to manipulate.