The Man Who Knew too Much (1984)

A young employee named Mehraban who is unhappy with his hard life meets a mysterious old man dressed in black. The old man says he will get Mehraban what he wants on the condition that he make the right use of his opportunities. Mehraban agrees. The old man leaves a newspaper with him dated three months in the future reporting the war between Iran and Iraq. Mehraban makes a lot of money by purchasing essential goods, hoarding them and then selling them later at much higher prices during the war. However he loses his fiancee and breaks with his friends. The mysterious old man appears again. He tells him he has abused his privileged opportunity and not to continue on the wrong path; on their last meeting he tells him he has become a monster and he must either to go back to his former life or die. The fear of death causes Mehraban to donate his illegitimate funds to charities and return to his honorable life.

Unfortunately the movie The Man Who Knew too Much is not yet available on HBO Max.