Tesla: Musk continues to be involved in the development of electric vehicles, including the production of the Model 3, Model S, and Model X. He has also announced plans to build new Gigafactories to increase production capacity and reduce costs.

SpaceX: Musk's aerospace company has continued to make progress in developing reusable rockets and space vehicles, with several successful launches and landings in recent years. The company has also been working on the Starship spacecraft, which is designed to carry humans to the Moon and Mars.

Neuralink: Musk's company focused on developing brain-machine interfaces has made progress in developing implantable devices that could allow humans to communicate directly with computers and other devices.

The Boring Company: Musk's tunneling company has been working on several high-profile projects, including a proposed tunnel system in Las Vegas and a project to build a high-speed transportation system between Washington, D.C., and Baltimore.

SolarCity: While SolarCity was merged into Tesla in 2016, it remains a part of Musk's broader portfolio and continues to work on developing solar power solutions for homes and businesses.