The Bitcoin Stock-to-Flow (S2F) model, introduced by pseudonymous analyst PlanB ahead of the 2020 halving, was once hailed for its apparent accuracy in predicting Bitcoin's (BTC) price action by modeling its programmed scarcity. The model divides the total existing supply (stock) by the annual new supply (flow), producing a value that increases after each halving event as the new coin issuance rate drops.
As of February 2026, with approximately 19.98 million BTC mined and an annual addition of around 164,250 coins, Bitcoin's S2F value stands at an impressive 121. This significantly exceeds gold's S2F value of roughly 60-65, theoretically positioning BTC as an even scarcer asset. The model's initial traction was bolstered by its successful correlation with Bitcoin's bull run following the 2020 halving, leading PlanB to frequently tout its accuracy on social media.
However, the model's reliability has faced mounting criticism and practical challenges in recent years. Analysts point out that the S2F model fundamentally ignores demand factors, which are crucial for price determination. Furthermore, its predictive power has faltered. Despite the S2F value crossing 100 after the 2024 halving, Bitcoin's price began to dip, contradicting the model's core thesis.
A significant deviation occurred in the 2024-2025 cycle. Bitcoin reached an all-time high (ATH) of $73,000 in March 2024 before the halving. Post-halving, a rally fueled by political hype pushed BTC to a new ATH of $126,000 in October 2025. Critics note that this peak was achieved with a similar S2F value to when BTC traded around $15,500 in late 2021, suggesting the model failed to forecast the magnitude of the move. If scarcity alone were the primary driver, prices should have theoretically surpassed $250,000-$300,000.
Today, the consensus among professionals is that the Bitcoin S2F model holds more value as an educational tool than a practical forecasting instrument. It effectively illustrates supply mechanics and draws parallels between Bitcoin and gold as stores of value. However, traders emphasize that no single analytical tool is sufficient; a combination of technical, fundamental, and on-chain analysis is required to navigate the intelligently moving market.
