What is the Stock-to-Flow-Ratio?

The stock-to-flow-ratio describes the rarity of a commodity. The valuation model comes from the traditional financial market and has been used for many years to value commodities such as gold and silver. It can also be applied to the digital asset Bitcoin. The higher the stock-to-flow ratio, the rarer the asset.

Stock-to-Flow as a valuation method

Precious metals and Bitcoin have the same problem when it comes to valuing them. Both assets have no cash flow. Therefore, the stock-to-flow ratio is often used as a valuation method for these assets, which uses the scarcity of a commodity, rather than their cash flow, for valuation.

Stock-to-flow-ratio means the ratio of stock to inflow. Stock is the current quantity of the commodity or good, i.e. the inventory. So in the case of gold or silver, this would be the total amount that has been mined throughout history. Flow is the quantity that is added annually to the already mined stock.

Origin Stock-to-Flow-Ratio

The stock-to-flow-ratio was first described by Hungarian Professor Fekete in 1997. The model puts with goods the already existing stock in relation to the annual increase by the production.

Calculation of Stock-to-Flow-Ratio

The stock-to-flow-ratio is calculated with the formula S2F = [Stock] / [Flow]. It indicates the time in years, which is needed to produce the currently available quantity of the good again. Thus, the scarcity of the good expressed in number of years.

Stock-to-flow-Ratio for Gold.

Gold, one of the rarest metals on Earth, has a very high stock-to-flow-ratio. According to the World Gold Council, over 205,000 tons have been mined as of 2017. In recent years, an average of about 3,100 tons of gold has been mined. Due to this rarity, gold has been the most stable money of all time.

Gold has a special role among commodities. The reason for this is that the industry consumes very little gold. So the majority of the mined quantity still exists somewhere. Mostly in the form of bars as a store of value.

This fact is also a reason for the good safety and stability of gold. The annual production is very low compared to the total amount of gold, therefore the S2F ratio is high. Thus, a loss of production or overproduction has almost no impact on the price of gold.

Calculation Stock-to-Flow-Ratio Gold

As of September 2022:
205,000 tons (Stock) / 3,100 tons (Annual Flow) = 66 years.

Stock-to-Flow-Ratio for other precious metals

For platinum, the S2F ratio is just about one year. For silver, a ratio of 22 years is documented. So while it only takes about one year for the current platinum production to double the current stock, it takes about 22 years for silver.

Stock-to-Flow-Ratio for bitcoin

The maximum amount of bitcoin is set by protocol. This maximum is 21 million Bitcoin.

In Bitcoin, stock refers to the already mined amount of Bitcoins or Satoshis in circulation. As of September 2022, the stock is approximately 19.1 million bitcoin.

Every 10 minutes a new block is mined and currently, as of 2022, is rewarded with the payout of 6.25 bitcoin per block. So per year this is approximately 52,560 blocks and 328,500 bitcoin. So the current annual flow is these 328,500 bitcoin. The stock-to-flow ratio is thus around 58 years, which is close to gold, which is currently around 66 years.

What is special about bitcoin, however, is that the flow is reduced on a planned basis every four years. Every four years, or every 210,000 blocks, the payout per block, also known as block subsidy, is halved. This halving of the reward for successfully mining a block is called halving. Through this mechanism, the total amount of Bitcoin will not be fully mined until the year 2140. Thus, the stock-to-flow ratio also continues to increase over time.

Calculation Stock-to-Flow-Ratio bitcoin

As of september 2022:
19’142’000 BTC (Stock) / 328’500 BTC (Annual Flow) = 58 years

Bitcoin Halving march 2024:
19’687’500 BTC (Stock) / 164’250 BTC (Annual Flow) = 119 years

Conclusion

As a limited resource, bitcoin is considered a scarce resource. A scarce good, is something that is physically rare or hard to find, such as precious metals, which are limited by nature. Once a commodity reaches a certain level of scarcity, it can be used as a store of value as long as there is some demand.

In bitcoin, future supply is very transparent and demonstrably scarce through mathematics. The Bitcoin price has historically risen sharply after each halving. This indicates a long-term positive trend in the bitcoin price. However, the price is subject to high short-term market overreactions and therefore fluctuates wildly.

Lost bitcoin make the bitcoin of others more valuable. Think of this as a donation to everyone. – Satoshi Nakamoto

However, it is clear that if the demand for bitcoin remains at least the same as it is at the moment, the price would have to rise in the long term, as the supply is demonstrably becoming scarcer. However, the demand for bitcoin has not remained the same in recent years, but has steadily increased.

> Learn why gold is valuable and why it has been used as a store of value for centuries.