One of the concerns I have with this market is the narrowness of it. In plainer terms, fewer and fewer stocks are doing the heavy lifting. With each successive peak in the S&P 500 (the black line), the number of stocks hitting new highs decreases (the blue line). That’s not a good sign.

Agreed. Same phenomena in the build up to the 2000 peak. Stocks fell away from about 1998…so it takes time.