I think your investment is $ 9000. So sell bitcoin and withdraw your investment, you can take profit from it, if you want

That's a very short run if he has to sell it right now but still, if you make a profit, that's a profit.

because the price of Bitcoin is making history. You can hold the rest.

He can sell and get back his capital if he wants to have it and don't touch the remaining amount as he withdraws.