Blackstone Inc. is an American alternative investment management company based in New York City. It was founded in 1985 as a mergers and acquisitions firm by Peter Peterson and Stephen Schwarzman, who had previously worked together at Lehman Brothers. Blackstone's private equity business has been one of the largest investors in leveraged buyouts in the last three decades, while its real estate business has actively acquired commercial real estate across the globe. Blackstone is also active in credit, infrastructure, hedge funds, secondaries, growth equity, and insurance solutions. As of September 2025, Blackstone had $1.2 trillion in total assets under management, making it the world's largest alternative investment firm.