While it is totally ok for anyone to sell his whole bag, look at what it does to the chart. This is not a CHAD move at all. Selling 11T for 750$ now is wasting the opportunity of selling 1.1T for 7500$ in 1 year (maybe).
Nonetheless, it's part of the game and sellers are also part of what makes GIGACHAD grow AND it also allows new buyers to get a good price.