The bias ratio is a statistical tool used to help finance professionals make more informed investment decisions. It measures the amount of risk associated with an investment by comparing the performance of different asset classes over time. By doing this, it provides a way to identify which assets are more likely to experience losses in value and which are more likely to generate positive returns.

The bias ratio is calculated by taking the average return of an asset class over a certain period of time and subtracting the return of a benchmark index, such as the S&P 500. The result is then divided by the standard deviation of the asset class’s returns.

A high bias ratio indicates that an asset class has outperformed its benchmark over the given period of time, while a low bias ratio indicates underperformance. A negative bias ratio indicates that the asset class has lost value relative to the benchmark.

The bias ratio is a useful tool for finance professionals because it can help them identify which assets are more likely to generate positive returns and which are more likely to experience losses in value. By understanding the risk associated with an investment, investors can make more informed decisions about where to allocate their capital.

Bias Ratio = (Average return of asset class – Return of benchmark index) / Standard deviation of asset class’s returns

Example:

For example, let’s say you’re considering investing in a new tech company. You know that the tech sector has been very volatile in recent years, so you want to use the bias ratio to help you make a decision.

You calculate the bias ratio of the tech sector by taking the average return of tech stocks over the past five years and subtracting the return of the S&P 500. The result is then divided by the standard deviation of tech stock returns.

The bias ratio for the tech sector comes out to be 1.2. This means that, on average, tech stocks have outperformed the S&P 500 by 1.2% over the past five years. However, they have also been more volatile, as indicated by the higher standard deviation.

Based on this information, you may decide that the tech sector is too risky for your investment portfolio and look for other opportunities.