Trump would use his father's $1M loan to buy condos that were undervalued because they were old and in need of fixing. He'd pay people to fix it up and paint it and turn around and flip it for more money. Then with the money he made flipping condos, he started to buy hotels and casinos and made his billions. Of course, he had to eat the costs sometimes and file bankruptcy but he never gave up until he was successful.

My son is learning how to flip houses, a lot of people do this, pay to fix them up and then sell them for more than they bought them for.