Is someone here that can tell me how it is possible to sell over a million of shares? Like I'm fairly sure this person didn't log into a web portal looked at h

Is someone here that can tell me how it is possible to sell over a million of shares? Like I'm fairly sure this person didn't log into a web portal looked at his stocks and then pressed the "sell" button and an hour later he has the money in his bank account. Or is it that easy for people like him?