Few voices in the crypto space have sparked as much debate as the mysterious analyst known only as Plan B. Operating anonymously since 2018, this Dutch institutional investor unleashed the Stock-to-Flow (S2F) model on the world — a framework that ties Bitcoin's price to its scarcity and has become one of the most cited — and contested — price prediction tools in digital assets.

Who Is Plan B and Why the Crypto World Listens

Plan B burst onto the Bitcoin scene in March 2019 with a Medium post titled "Modeling Bitcoin's Value with Scarcity." The thesis was simple yet electrifying: Bitcoin, like gold, silver, and platinum, derives its value from how rare it is. By quantifying that rarity, one could model where Bitcoin's price should go.

Unlike many Twitter pundits, Plan B brought credentials. He is widely believed to be a Dutch institutional investor with decades of experience in traditional finance and risk management. That pedigree gave his model weight, and his anonymous identity — confirmed in interviews with financial media — only amplified the intrigue.

  • First major S2F article published March 2019
  • Later refined into the S2FX model, incorporating multiple asset classes
  • Maintains a followership of over a million across X and YouTube
"Bitcoin is the first scarce digital object the world has ever seen. It is scarce like silver and gold, and can be sent over the internet, anywhere in the world." — Plan B

How the Stock-to-Flow Model Actually Works

The core idea borrows from commodities markets. Stock refers to the existing supply of an asset, while flow measures new production. The ratio between them — the S2F — essentially tells you how many years it would take to double the current supply at today's production rate. The higher the number, the scarcer the asset.

Gold sits around an S2F of 62. Silver hovers near 22. Bitcoin, thanks to its programmatic halving every four years, climbs the scarcity ladder each cycle. Plan B's original chart plotted Bitcoin's monthly price against its S2F and produced an almost eerily tight fit — a power-law relationship suggesting that as Bitcoin's stock-to-flow rises, so does its market value.

The Halving Engine Behind the Scarcity

Every 210,000 blocks — roughly every four years — Bitcoin's block reward is cut in half. This event, known as the halving, is the flywheel of the S2F model. With each halving, new supply growth slows, pushing the stock-to-flow ratio higher and, theoretically, the price along with it.

  • 2009: 50 BTC per block
  • 2012 halving: 25 BTC per block
  • 2016 halving: 12.5 BTC per block
  • 2020 halving: 6.25 BTC per block
  • 2024 halving: 3.125 BTC per block

Each cut shrinks flow by 50%, dramatically reshaping Bitcoin's scarcity profile and, according to Plan B, its long-term valuation.

The Predictions That Shook Markets

In his original model, Plan B projected Bitcoin could reach $55,000 by 2021. When BTC surged past $64,000 in April 2021, the model looked prescient. He then unveiled the S2FX model, which cross-references Bitcoin with gold, silver, and diamonds — positioning BTC as a store-of-value asset on a much grander scale. That updated framework hinted at valuations of $288,000 per coin in the current cycle.

Market watchers, hedge funds, and even corporate treasury teams cited Plan B's work as part of their bullish thesis. Some of his YouTube interviews have drawn hundreds of thousands of views, and his charts circulate across crypto Twitter every cycle.

Criticisms and the Limits of the Model

Not everyone is convinced. Critics have raised several pointed objections since the model's debut. Chief among them is the risk of overfitting — a statistical pitfall where a model hugs past data so tightly that it fails to predict the future. With only a handful of Bitcoin halvings to work with, skeptics argue the data sample is simply too small for such confident forecasting.

Other concerns include:

  • Black swan events: The model assumes orderly markets, but crashes, regulation, or technological shifts can break any linear pattern.
  • Demand assumptions: S2F measures supply, not demand. A falling interest in Bitcoin could leave scarcity theoretical.
  • Survivorship bias: The model fits historical data; whether it remains valid in a maturing, ETF-dominated market is an open question.

When Bitcoin traded sideways through much of 2022 and 2023 — well below the model's projected trajectory — Plan B's critics grew louder. Even he has acknowledged the model has "two regimes," and he has recalibrated expectations more than once.

What Plan B Says Now — and What Comes Next

Despite the criticism, Plan B continues publishing charts and updates. His recent commentary suggests Bitcoin remains in a long-term bull market, with the 2024 halving acting as the next major catalyst. He has hinted at multi-cycle targets that stretch well into six figures, though with growing humility about timing.

Whether you treat Plan B as an oracle or a useful contrarian gauge, his influence is undeniable. He forced a generation of analysts to take scarcity-based modeling seriously and reframed Bitcoin's narrative from "digital cash" to "programmable scarcity."

Key Takeaways

  • Plan B is an anonymous Dutch institutional investor whose Stock-to-Flow model links Bitcoin's price to its scarcity.
  • The model relies on Bitcoin's four-year halving cycle to drive the stock-to-flow ratio upward.
  • Original S2F and the newer S2FX model have predicted prices ranging from $55,000 to $288,000 per BTC.
  • Main criticisms include overfitting, small data samples, and ignoring demand-side dynamics.
  • Even if imperfect, Plan B's framework reshaped how the world thinks about Bitcoin as a scarce digital asset.