The company is just scratching the surface of its growth potential.Robinhood Markets (HOOD 3.12%) is breaking a new mold in the fintech market. The stock has rocketed 490% higher over the past year, sending its market cap toward $100 billion.While the stock might look overbought after such a steep rally, its customer assets are still very small compared to other leading financial service companies, which leaves plenty of room for the company (and stock) to grow in value over the long term. The more services ...