Nathaniel Horwitz

Horwitz was born in Washington D.C. to Tony Horwitz and Geraldine Brooks, the elder of two sons.^[3] The family split time between Sydney, Massachusetts, and Virginia.^[4][5]

As a student, Horwitz worked on biotech startups.^[6][7] While at Harvard, Horwitz met Sam Koppelman, with whom he would later found Mayday Health and Hunterbrook.^[8][9]

After graduating from Harvard, Horwitz joined RA Capital Management, a healthcare-focused investment firm.^[10] While at RA Capital, Horwitz launched biotech companies.^[11] He left RA Capital in 2023, before founding Hunterbrook.^[12]

In 2022 Horwitz co-founded Mayday Health with Koppelman and Liv Raisner.^[13] The 501(c)(3) nonprofit educates on abortion access and advocated for laws to shield healthcare providers who send abortion medicine to people in states with abortion bans.^[14]

In 2023, Horwitz and Koppelman founded Hunterbrook, an investment fund and investigative journalism outlet,^[15][16] with Horwitz as CEO. Hunterbrook later raised $100 million in 2024 "to make trades based on articles by its affiliated newsroom.”^[17][18] The company's name is partially derived from Horwitz's mother's last name.^[19]