Surprisingly mythologically accurate.
Djinn didn't (originally) have reality-bending wish-granting powers. They were just powerful semi-immortal spirits, akin to the earthly equivalent of angels, and tended to be rich.
Thus any "wish" granted wasn't a genie-snaps-fingers-reality-is-changed sort of thing so much as you freed a rich, immortal magical being from a spell put it on by Solomon and said jinn now offers you a favor as a show of gratitude.
But risky stocks are probably not the way to do it.
The title said "powerful", not "smart".