The asset value-investor value ratio is the relationship between active capitalization (ActiveCap), which is the BTC that is in motion at a given time, and investors' realized capitalization (InverstorCap).

The investors realized price capitalization (InvertorCap) is the realized capital (RealizedCap), which is the price at which the BTC have been purchased but discounting what was delivered to the miners.

The AVIV ratio, then, is a way to measure what proportion of the money in Bitcoin is actually in motion, active capitalization, compared to how much money investors have invested in total, Investor realized capitalization.

When this ratio is above 250%, it suggests that Bitcoin is overvalued and a recession is likely to begin, as there is a large amount of money in motion relative to the investment made.
On the other hand, when the ratio is below 55%, it indicates oversold and an upward trend, since there is relatively little money in movement compared to the investment made, which suggests that there may be interesting investment opportunities.

More information in the white paper of Cointime Economics on @ARKInvest by @dpuellARK and @Checkmatey