Tesla has quietly zoomed past another automotive milestone. Just a week after the company surpassed Ford Motor in market value, its shares closed at $312.39 on Monday, making Tesla worth about $50.9 billion, slightly more than General Motors.

G.M., like Ford Motor, has been operating for more than 100 years, and in the first quarter of 2017, it sold hundreds of thousands more vehicles than Tesla, an electric car upstart, did in all of 2016. But investors are betting that Tesla, whose chief executive is Elon Musk, has room to grow as the world’s appetite for electric vehicles expands.