Tesla launched the Model S, the first car built on its own platform, in 2012.
Tesla began customer deliveries of the Model S in June 2012. Unlike the earlier Roadster, which used a modified Lotus Elise chassis, the Model S was designed as a purpose-built electric sedan on Tesla's own platform. Its long range and software-centered features helped make battery-electric cars more prominent in the premium market.
Tesla's market capitalization rose sharply as investors priced in expectations for rapid electric-vehicle growth, energy storage, charging infrastructure, and software. Market cap reflects investor expectations as well as current sales, so it can change much faster than a company's physical assets.
The Model S was not Tesla's first vehicle: the Roadster preceded it. Nor was it the first modern electric car generally. Its significance was combining a long-range battery system with a scalable company-owned vehicle platform.