Joel Tillinghast: avoid investing in the single largest stock in the S&P 500

Familiarity can work against investors.  If you continuously invested in the single largest S&P 500 stock by market value between 1972 and 2016, your compound returns would have been less than 4 percent, while the index earned over 10 percent.  A smiliar but smaller effect was seen with the ten largest S&P 500 stocks.

~ Joel Tillinghast, Big Money Thinks Small, p. 60

Warren Buffett on how size will limit performance

We face another obstacle: In a finite world, high growth rates must self-destruct. If the base from which the growth is taking place is tiny, this law may not operate for a time. But when the base balloons, the party ends: A high growth rate eventually forges its own anchor. 

~ Warren Buffett, Berkshire Hathaway 1989 Annual Report, March 2, 1990