Timothy Dexter. A man who was completely uneducated, he managed to make a fortune by making a series of horrible business decisions that, due to luck, turned out to be extremely profitable. The man made the stupidest decisions possible (including a number suggested by hated enemies) and every one of them came out as a profit. Some examples:
Stocking up on Continental dollars during the Revolutionary War. None of the people who made the suggestion ever gave thought to the possibility that the colonies would win...which they did.
On marrying a wealthy widow, he decided to play the stock market. By picking stocks at random. They all went up.
Selling the strangest things to the Caribbean:
Bed warming pans, which you don't need in the tropics. But the warming pans turned out to be great for straining molasses.
Stray cats. But it turned out the Caribbean was having a rat problem.
Mittens. But traders there bound for Siberia took them off his hands.
He sent Bibles to the East Indies, a not-exactly-Christian area. Except there were missionaries over there at the same time, eager to use the bibles to spread Christianity in the area.
Sending coal to Newcastle. As in a place built on the coal-mining industry (thus the phrase "Coals to Newcastle" meaning "giving them something they have too much of already"). What happened just before it got there? The coal miners went on strike and bought all his coal.
Stocking up warehouses full of whale bones. Then someone discovered that whalebone made an ideal reinforcing material for corsets. He sold clean out.