Commodity-backed stablecoins
Commodity-backed stablecoins have reserves made up of physical assets, such as precious metals, real estate, and oil. The most common type of commodities used to back stablecoins are precious metals, specifically gold.
This type of stablecoin is pegged to its reserve asset. For example, a gold-backed stablecoin would be pegged to the value of gold. The advantage for investors is that they can purchase digital versions of commodities without needing to obtain or store the actual physical asset.
Algorithmic stablecoins
Algorithmic stablecoins control the circulating supply using algorithms and smart contracts. They may not have reserves, and, if they do, they're typically under-collateralized. Algorithms reduce the supply if the stablecoin's price is lower than the asset it tracks and mint more coins if it's higher. It's similar to how central banks operate by printing and destroying fiat money.
These stablecoins are riskier because they don't have sufficient reserves to dip into if they face issues. TerraUSD (USTC +9.64%) is a famous example of how this can go wrong. This algorithmic stablecoin lost its peg in May 2022, and the value plummeted.
What makes stablecoins unique?
The thing that makes stablecoins different is that they mimic another asset's value. Other cryptocurrencies have prices based on what they offer and market demand; stablecoin prices depend on the asset they're following.
This gives stablecoins some advantages over traditional cryptocurrencies. Most notably, a stablecoin is much better suited for being an actual digital currency that you can store, transfer, or use to pay for goods and services. Because it has a stable value, you don't need to worry about price fluctuations.
Where stablecoins came from
J.R. Willett, a member of the early Bitcoin community, is considered the inventor of stablecoins. He came up with the idea of asset-pegged cryptocurrencies in 2012 and mentioned it in the white paper for his MasterCoin protocol.
