Cryptocurrency prices will tank because of this and the Bitcoin fork. I'm going to load up as much as possible in this period.

I don't really understand the end game of the international police force that took down Alphabay. Alphabay users will just move to another market, that market will probably be shut down in a year and the process will repeat. There are literally hundreds of reliable markets.

As long as you are careful to use good security (PGP etc.) and don't tie up too much capital in your account there is no great risk.