PlanB is the pseudonym of an anonymous Twitter user who goes by the handle @100trillionUSD. He has 1.8 million followers.

Plan B became well-known within the cryptocurrency community for his work on the "stock-to-flow" (S2F) model, which aims to predict the price of Bitcoin based on its scarcity.

The model suggests Bitcoin going to $1 million then $10 million… eventually.

Although PlanB’s real identity has never been revealed, from interviews we know he’s a Dutch male in his late 40s. He has a law degree and a degree in qualitative economics.

He has been a trader and investor for 25 years, and in 2021-22 left paid employment to focus full-time being a Bitcoin educator and influencer.

On the Coin Stories podcast in June 2021, host Natalie Brunell delved into his background. As a child he was into astronomy and navigation. To this day he is a keen sailor, and likes navigating by the stars.

At university he started dabbling in investing. He notes that the Dutch people have always been great traders, and been interested in having money work for them, rather than just woring for money. The stock market is a Dutch invention.

In the 15 years up to 2021-22, PlanB was an institutional investor. He managed a team of 10 people investing bank savings, pension money, and insurance funds.

Most of this investing was in very safe things like bonds and fixed income, but in early 2013 Bitcoin came onto his radar. He read Satoshi’s White Paper on Bitcoin. “It hooked me in. So brilliantly written. Only nine pages including references. It just hit me.”

Going down the Bitcoin rabbit hole to educate himself, it was a year before Plan B committed any money.