PlanB

S2F model (controversial but a defining public framework)

PlanB is a pseudonymous Dutch institutional investor and quantitative analyst active primarily on social media. They published the Bitcoin Stock-to-Flow model in 2019, arguing that Bitcoin's fixed supply schedule predicts price appreciation similarly to gold and silver. The model became one of the most widely cited—and disputed—frameworks in crypto, later extended to the cross-asset S2FX variant.