How do big companies store their Bitcoin?

I just read an article here in this Subreddit that MicroStrategy is one of the biggest Bitcoin holders in the world. The hold billions with of Bitcoin.

This made me think: how do they store their Bitcoin? Is there a guy dwsicatwd only to do so? Carrying thad paper wallet ;) do thei use Ledger? Or is it insanly unsafe stored in a hot wallet and people in Charge don't know better or dont care?

I would love hear an insider what's all the processes / mechanics are to transfer / liquidate some of the Bitcoins are.

And no, I'm not planning a heist, I'm just curious about the process. With all the incompetence especially in the business world (everybody pretends to know it all but knows jack shit and gets away with it) I would love to know more.

But I'm sure we will only find out if Bitcoin of such companies get stolen ????