Timothy A. Springer Net Worth

Timothy A. Springer has an estimated net worth of $3.2 billion, according to Forbes Real-Time Billionaires, Timothy A. Springer profile (figures as of October 20, 2026). That is up from $2.2 billion in 2021.

Timothy A. Springer is an immunologist and professor of biological chemistry and molecular pharmacology at Harvard Medical School. He started teaching at Harvard in 1977 as an assistant professor and built a career in research while staying active in biotech. He is known for work on cell adhesion, integrins, vascular biology, and immune regulation. Alongside his academic work, he became a founder and investor in biotechnology companies, turning his scientific background into major business value.

His wealth comes from biotech investing and company building. In 1993, he founded LeukoSite, a biotech company that went public in 1998. The next year, he sold it to Millennium Therapeutics for $635 million. He was also a founding investor in Moderna, putting in about $5 million in 2010, and he now owns an estimated 3% of its shares. He also owns shares in Cartesian Therapeutics, Scholar Rock, and Tectonic Therapeutic.

How Timothy A. Springer built his wealth

Springer made his money by pairing a long academic career with early bets on biotech. At Harvard Medical School, he built his name as a scientist while continuing to run an NIH-funded laboratory and start companies. His best-known company move came in 1993, when he founded LeukoSite. After the company went public in 1998, it was sold the next year to Millennium Therapeutics for $635 million, giving him a major business success tied to his scientific work.

Another big part of his fortune comes from Moderna. Springer was a founding investor in the public biotech company and invested about $5 million in 2010. Forbes says he now owns an estimated 3% of the firm’s shares. He also holds shares in Cartesian Therapeutics, Scholar Rock, and Tectonic Therapeutic. In 2017, he also launched the Institute for Protein Innovation with an initial grant of $10 million, adding an independent nonprofit research effort to his biotech career.

Forbes net worth over time

Forbes has tracked Springer’s fortune across several years, with estimates that moved sharply. It put his net worth at $2.2 billion in 2021, then $2.1 billion in 2022 and again in 2023. The estimate later fell to $1.5 billion in 2024 and $1.1 billion in 2025. Those swings fit a fortune tied to public biotech holdings, where market prices can change fast and affect the value of large stock positions.

As of October 20, 2026, Forbes' real-time billionaires tracker estimated Springer’s net worth at $3.2 billion. That real-time figure was much higher than the $1.1 billion Forbes listed for 2026 on its annual World’s Billionaires List. The main drivers named in his profile are his Moderna stake and his holdings in other public biotech companies. Forbes also classifies him as self-made and places his wealth in healthcare, with biotech as the source.