He could have exited for tens of millions (somewhere around 30 or 40) but held. As for my own two cents, he wasn't holding to make a point or pump the stock, but was instead sticking to his guns and following his own publicized strategy of not entering or exiting a position all at once. People read too much into his screenshots without bothering to know much else about him (e.g. his YouTube channel).

edit for clarity: The 13+ million that he did exit with is therefore a smaller chunk of what he could have made.