SUNNY ISLES BEACH, FL – (VINnews) Leonid Radvinsky, the billionaire owner of several technology sites, died at age 43 following a prolonged illness, the company said Monday.

Radvinsky, a Ukrainian-born American entrepreneur, acquired several social media sites in 2018 and built it into a global business that saw rapid growth in recent years.

He had an estimated net worth of about $7.8 billion, according to Forbes.

Born in Odesa, Ukraine, Radvinsky immigrated to the United States as a child and was raised in a Jewish family. He was widely associated with Chicago before later moving to Sunny Isles Beach and kept a low public profile despite his role in shaping one of the most prominent platforms in the digital content industry.

In 2024, he was linked in reports to a potential $11 million pledge to the American Israel Public Affairs Committee following the Oct. 7, 2023, attacks. Radvinsky denied making or pledging the donation, saying in a statement that neither he, his foundation nor his family had committed the funds. However, reporting at the time cited internal documents attributing the contribution to an anonymous donor and his wife, Katie Chudnovsky, including a wire transfer associated with her.

Radvinsky and his wife were also known to have made significant contributions to cancer research in recent years, according to people familiar with their philanthropy.

He is survived by his wife, and their four children.

In a statement, the company said he “passed away peacefully” and asked that his family’s privacy be respected.

No further details were immediately released.