The first half of 2021 has seen one of the best, most consistent, and most persistent rallies year-to-date in the S&P 500’s history.

The good news is that such strong momentum tends to persist over the long term, and positive returns over the following 6-month and one-year periods, are a highly probable outcome.

On the other hand, the S&P 500 and Nasdaq have reached lofty heights, and these advances are carried by fewer and fewer stocks. Signs of a fragile market are increasing at a time that is seasonally weak for the market.