Quantity, Josef Stalin allegedly said, has a quality all of its own. This is true of the US stock market. Much has been written about the top-heaviness of US stocks, and more will surely follow, now that the market cap of Nvidia has exceeded Apple for the first time. (Next up: Microsoft).

I’ve been writing about this for some time, starting in 2016 with an article quaintly entitled ‘Giants of the S&P 500’. In those innocent times, when Apple was still an $630 billion company, the largest six stocks accounted for 14% of the total index market cap, which seemed like a big deal to me back then. But now look at the situation in the chart below, where the largest six stocks currently have a market cap almost 32% of the index.