Nah that's not it, it should be the exchange, maybe before personal wallets would had been the idea recommendation since we all advocate for been in control of your keys but with the high fees this days it won't be idea since you could spend almost all your profit just for fees if you're moving coins from personal wallet to exchange each time you want to sell.
The high fees aren't affecting just bitcoin but coins on ethereum blockchain are also in the same shit. With that in mind, selecting the best exchange with very good good reputation that you can keep your trading funds in would be the idea first step.
You should know though this fund should be strictly for trading and they should be funds you'll comfortable if the worst case scenario would happen.
Having said that, judging by the size of mempool Bitcoin transaction fees are down this day.