Testosterone at Series A vs. Series B (SHOCKING). #yc #funding #startup
6 Sept 2025 · 1 min

0:52
YouTube video (by Anne Truong MD, uploaded Sept 6, 2025) reporting on a study measuring testosterone in 107 male Y Combinator founders across funding stages. The spoken transcript summarizes that testosterone is in a healthy range pre-funding, surges at Seed, steadily rises through Series A, reaches a peak at Series B higher than pre-funding peak, then drops massively (42%) in a late BC phase — suggesting many founders ran below optimal testosterone until late-stage funding.
Questions this video answers
107 male founders.
42% drop (described as a "massiven Abfall von 42 Prozent").
Pre-funding, Seed, Series A, Series B, and a late BC phase.










