[keebEz]

VIX attempts to measure volatility but it is not volatility itself. The lowness of VIX has been driven by the relative increase of the denominator (total asset value, which has surged in the last few years) not by a decrease of the numerator.

In general, it's usefulness as an indicator of volatility has decreased lately.

[marshray]

VIX measures the risk premium on options on the S&P 500 index. I don't see how total asset value ends up in the denominator?

Another explanation is that VIX is being actively dampened by the growing popularity of the 'short volatility' trade. E.g., the SVXY ETF among others. We're seeing today just how volatile volatility can be!