Thsi time last year he owned a lot of options -- the ability to buy thousands of shares at a low price (like $5 each, when the shares were selling at $200). Typically you can sell those options and take the cash, but you can simply pay for the shares instead.

Each month he'd post an update which said he bought the shares instead.

Obviously he could have faked the screenshots, but he also swore to congress when the price was c. $40 (after the initial $400 spike) that he would still buy Gamestop at $40. A few days later he posted another screenshot showing not only did he exercise his final options, but he bought even more at around $40.

Now he could have sold most of his shares at any point in the last 9 months, which mostly bounced between $150 and $250, or he could have kept them just like the Gamestop board did (indeed I believe some of the board actually bought more shares at those overinflated (imo) prices. Nobody knows.

I believe one way of making money without selling is to sell options -- you tell someone "I will guarantee to sell 100 shares for $150 a share on May 1st" for example. They will pay you $3 a share for that guarantee, and when the price on May 1st is $140 you just laugh. If the price is $160, you have to sell your shares for less than market price (but still more than you paid), and eat the loss.

The article didn't actually have any new information, as far as I'm aware no one knows what he has done since he went quiet.

Yup, Spoiler alert - They asked him what he was doing now. He didn't reply.