A ratio attempted to price Dow in terms of Gold. Measuring Dow in terms of Gold is an effective way rather than dollar based due to the nature of currency supply based on number of factors. Gold on the other has survive d for centuries and is stable way of pricing of other asset classes.
The ratio has seen ups and downs and runs in cycles from one end to another reflecting one asset getting overvalued and the other being undervalued.
The last gold bull spawned in 70's took price to $850 (overvalued) and then moved all the way to $250ish (undervalued).
This blog is an attempt to archive the progress of the ratio.