Gates manages his personal investments through Cascade Investment LLC, a holding and investment company. Cascade Investment has holdings in various sectors, including real estate, energy, and transportation.

Gates invests in Beyond Meat, a company that produces plant-based meat alternatives, reflecting his interest in sustainable food production and reducing the environmental impact of meat consumption.

Gates invests in and promotes innovative water purification technologies, such as the OmniProcessor, aimed at providing safe drinking water in developing countries and addressing sanitation challenges.

Gates co-founds TerraPower, a company that develops advanced nuclear reactor technology, with the goal of providing cleaner, safer, and more affordable energy.

Invests in Ecovative Design, a company that grows sustainable materials from mycelium (mushroom roots) as an alternative to plastics and other environmentally harmful materials.

Invests in Carbon Engineering, a company developing Direct Air Capture (DAC) technology to remove carbon dioxide directly from the atmosphere, aimed at mitigating climate change.

Gates is a key investor in Breakthrough Energy Ventures, a venture capital fund that invests in companies developing breakthrough technologies to address climate change across various sectors, including energy, agriculture, and transportation.

Through Cascade Investment and other vehicles, Gates maintains a diversified portfolio of investments across various sectors, reflecting his long-term investment strategy and commitment to supporting innovative and impactful businesses.