If Bitcoin price pumps from $1300 to $3000 in few hours, nobody would make profit from it, because the exchanges wouldn't allow you to sell your Bitcoins and make the fast profit, it would bring a big loss for exchange sites.
Do you agree with this?
What?
Why would the exchanges not allow for their users to sell their Bitcoins in the event of something like this? You almost never sell to the exchange itself, always to other people. If others are buying it for that value, then the exchange should just let it happen since it doesn't affect them.
Are you sure you know how most exchanges work? You're kind of making me think you think that you only ever sell to the exchange.
I saw days ago a thread about exchanges legitimacy. Some people think it's just a question of time until all exchanges close and scam its users. With a big pump on Bitcoin price, the exchange owner's could imagine a possibility of high fast profit, principally if they have a big Bitcoin volume on their site, under their control.
The transactions could be freezed, they could use the user's Bitcoins to make profit for themselves, selling and buying again later cheaper on another exchange for an example... Or, the worse scenary, they could scam everyone and make all the profit for themselves. I'm not saying it will happen, it's just a possibility on the situation Bitcoin pumps a lot in a small time period, and I'm asking what you think about it.