IV is implied volatility
HV is historic realized volatility
Seneca teaches that we often suffer more in our minds than in reality, and the same is true with the stock market. This indicator can help identify when people are over paying for implied volatility relative to real volatility . This means that short sellers are over paying for puts and can be squeezed into covering their positions, resulting in a massive rally.
The indicator can track this spread over many time frames, when the short time frame is much higher than the lower time frames, consider it a signal-of-interest.