> 2 Size. While the US economy’s size is over $21T, the stock market (here we use the S&P 500, SPY, as a proxy) is at present worth approximately $40T, so nearl

> 2 Size. While the US economy’s size is over $21T, the stock market (here we use the S&P 500, SPY, as a proxy) is at present worth approximately $40T, so nearly 2x bigger. However, the stock market’s value can fluctuate significantly. In a downturn, the stock market’s value can converge roughly to the size of the overall economy. This is total an utter garbage - I stopped reading after this; they seem to be confusing different units of $'s. My house is "worth" 15x my "income" and my "income" is 1/25th of my net worth (and was 200x my net worth when I was 25). There are times these numbers may converge, but it wont tell you which pair of underpants I have on that day. They could have made a point about prices vs earnings - which gdp / market cap would give some measure of (if you believed that the stock market was a reasonable measure of the market cap of the country) which is almost certainly what the Buffett metric they go on to mention would be motivated by.