“I’ve systematized my study of bubbles over time into a “bubble indicator” based on six influences, which are combined into gauges. We do this for each stock that we are looking at, then these gauges are combined into aggregate indices by security and then for the market as a whole. This chart shows the aggregate reading derived by combining these gauges into one reading for the stock market going back to 1910. It shows how the conditions stack up today for US equities in relation to past times. In brief, the aggregate bubble gauge is around the 77th percentile today for the US stock market overall. In the bubble of 2000 and the bubble of 1929, this aggregate gauge had a 100th percentile read.”