I have read dozens of threads saying you need to keep your BTC on a hardware wallet or paper. Anything online isn't safe they say. When trading that is not really feasible is it? I like to move in and out of positions several times a day and often at a moments notice. My trading account has a sizable balance (to me - 5 figures) in it.
How risky is this and any additional things I could do?
I think if you are a trader, and you operate on large trading floors, you do not need to worry about security. Because they always make sure you are safe about security issues, however, you also need to do everything right according to their needs.