As can be seen from the table below, their prices all have means near $1.00 USD, with DAI being the closest by mean. Their variances are also small with USDC having the smallest:

Table — Mean and Variance of Price (based on 365-day-window)

Above we also attached statistics for ETH and BTC as the major coin for comparison. The variance are normalized by N-1.

Unlike the rest of the cryptocurrency market, stablecoins should not be subject to dramatic price swings. One measure of the volatility in stablecoin prices is its beta value relative to major cryptocurrency markets such as those for Bitcoin and Ethereum. Here is a table of betas for several major stablecoins relative to Bitcoin and Ethereum:

Table — Beta Coefficient of Stablecoins vs. ETH/BTC (based on 365-day-window)

A token will have a beta coefficient of 1 with itself. It serves as a threshold for risk measurement in practice of stock market analysis:

When beta >1, it means the stock is more volatile than the market benchmark (usually SP500 index for stock market). It can also be interpreted as sensitive to the market changes. For example, when the market fluctuates, the stock will be influenced largely and bring higher yield, as well as higher risk;

When beta =1, they have the same level of volatility;

When 0<beta <1, the stock is less likely affected by the market trend.

Usually stocks are positively correlated with the market, i.e. the beta coefficient are usually positive values. However, there are also cases when the value is negative, where stock’s price will go up when the market is at fall.

For the 5 stablecoins above, we see that all of them have absolute values smaller than 0.1, which means they are all much more stable than ETH and BTC, and are unlikely to be affected by the cryptocurrency market trend. In appendix, we also attached a table of beta coefficients for other top coins, for comparison.

Among them, USDC and TUSD have the smallest values and show a negative correlation with ETH and BTC, this indicates that they serve as “storage” tokens to avoid risks when the market is unstable: when ETH/BTC market is going up, users are likely to sell TUSD/USDC to enter the market; when the market is at fall, users may swap their holdings for TUSD/USDC for asset preservation.