Leonard Schleifer vs Mark Zuckerberg
Real-time net worth, career, and company comparison — updated June 2026.
Wealth at a Glance
Net worth gap: $205.2B — equivalent to 99% of Mark's total wealth.
Tale of the Tape
Career Highlights
Leonard Schleifer
- 1988Founded Regeneron PharmaceuticalsCo-founded Regeneron Pharmaceuticals with George Yancopoulos, which has become a leading biotechnology company.
- 1991Regeneron went publicTook Regeneron public on the NASDAQ.
- 2011Eylea ApprovalOversaw the approval of Eylea, a successful treatment for age-related macular degeneration, which became a blockbuster drug.
- 2020COVID-19 ResponseLed the development of an antibody cocktail for the treatment and prevention of COVID-19.
- 2025Biotechnology Heritage AwardReceived the Biotechnology Heritage Award from the Science History Institute and Biotechnology Innovation Organization.
Mark Zuckerberg
- 2004Founded FacebookCo-founded Facebook while at Harvard University.
- 2008Became a BillionaireBecame a billionaire at age 23.
- 2012Facebook IPOTook Facebook public, making it one of the largest IPOs in history.
- 2021Meta RebrandingFacebook rebranded to Meta Platforms, Inc., focusing on the metaverse.
Net Worth History
| Year | Leonard | Mark | Leader |
|---|---|---|---|
| 2020 | $2.5B | — | — |
| 2022 | — | $65B | — |
| 2023 | — | $170B | — |
| 2024 | $2.9B | $224.1B | Mark |
| 2025 | $2.8B | $222B | Mark |
| 2026 | $2.463B | $207.68B | Mark |
The Verdict: Mark Zuckerberg vs Leonard Schleifer
As of June 2026, Mark Zuckerberg leads this comparison with a net worth of $207.68B, placing at #6 in the global rankings. Leonard Schleifer follows at $2.463B — a gap of $205.2B.
The two leaders come from distinct industries — Healthcare for Leonard Schleifer and Technology for Mark Zuckerberg. Comparing them is therefore a comparison of different underlying asset types, growth rates, and risk profiles rather than a simple head-to-head within the same market.
Leonard Schleifer is 73 years old versus 41 for Mark Zuckerberg, a difference of 32 years. Age context matters in wealth comparisons: a younger billionaire at the same net worth has had less time to accumulate — and in many cases represents a higher compound annual growth rate on their wealth.
Net worth figures are estimates calculated from public shareholding disclosures, stock price data, and reported asset values. See our full methodology.
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Net worth estimates updated daily from public financial disclosures. Methodology · Report an error