Ride-hailing, which involves booking transportation services via a smartphone app, is a two-horse race in the United States. Aside from legacy taxis, Uber Technologies (UBER -2.85%) and Lyft (LYFT 0.03%) are the dominant players. Uber is the market-share leader and an industry Goliath, while Lyft is a smaller competitor that might promise more upside as the underdog. Which stock is the better investment today? It's a head-to-head you don't want to miss. Uber's held onto its market share over time Uber and L ...