Reinvest it in BTC as soon as the price drops (it eventually will, but when?)
My advice for you is: Split your money after taking profit into 2 part: part 1 is for the initial capital that you should keep in fiat. Part 2 is the profit you get so far. You can reinvest by the part 2. In bad investment, you will not lose your capital, and only lose all your profits or have left money from your profit if the reinvestment get a loss of 50%, 80% or 90%.
It gives you a safe reinvestment. If you are right, and get luck, you can earn more profit. If not, you will still have your initial capital to use.
Securing your initial investment would be the best thing should be done or to prioritize but there are people who do really tend to risk on making some compounding thing for the chance for them
to make that investment make more bigger.
Initial investment + profits = Bigger investment = Bigger profits but always think that you will really be missing out on making profits in short time but you know that you are really
sacrificing it for the sake of bigger profits later on.
If you cant take up the risk then you do want to secure your initial investment then its your choice.If you do really trade well then those profits of yours will really still grow.