Is there any sin on one who bought shares on the stock market, then sold them at a higher price after discovering that a portion of the company's profits resulted from bank deposits and treasury bills?

The authoritative fatwa according to us is the prohibition of buying shares in mixed companies that deal with usury in some of their transactions. Therefore, you must repent and not return to buying such shares. To dispose of the impermissible amount when selling them, you can refer to fatwas no. 152899 and no. 49853.