Elon Musk just spent $1 billion on Tesla shares. He'll have to spend a lot more to ramp up his control.

Elon Musk just spent $1 billion on Tesla shares. It's only a small step toward tightening his grip on the EV maker. Tesla's CEO bought around 2.6 million shares of the EV maker on Friday, a regulatory filing revealed on Monday. The purchases increased his share count by just 0.6% to around 413 million shares, lifting his ownership stake from roughly 12.7% to 12.8%.The 304 million shares from his 2018 compensation plan, which remain tied up in legal disputes, were not included in the filing. In calculating ...