No – when you take money out of your crypto wallet, the online poker room will convert your coins to the desired currency, which usually is USD. While the money is in your poker account, the value of your money will not change as your funds are not invested in the crypto account. When you go to withdraw it back to your wallet, the poker site will sell you back coins at the market value, minus transaction fees and after that, it will be subject to fluctuations in the market price.