I've read that they've bought again this plummet and that's around 9000+ BTCs again.

I'll choose to do it on BTC and will have my money entrusted on it than to invest on their stock that also buys Bitcoin. You see the loop there? if you can invest and buy BTC while you're going to invest to a company that continuously buys it and then the gains will mostly go to them and through their stock or share, they'll distribute that profits wherein you can maximize that profit by having BTC in your own custody.