Contrary to popular belief, earnings growth has a very low correlation with decadal stock returns. The primary driver is the change in the valuation multiple (e.g., P/E ratio expansion or contraction). The correlation between 10-year real returns and 10-year valuation changes is a staggering 0.9, while it is tiny for earnings growth.

A key tension in modern investing is that the best businesses often appear perpetually expensive (e.g., 30x+ P/E). However, their ability to continue delivering double-digit returns challenges the core value investing principle of buying at a low multiple, demonstrating the immense power of long-term quality and compounding.

Counter to conventional value investing wisdom, a low Price-to-Earnings (P/E) ratio is often a "value trap" that exists for a valid, negative reason. A high P/E, conversely, is a more reliable indicator that a stock may be overvalued and worth selling. This suggests avoiding cheap stocks is more important than simply finding them.

Shelby Davis's core strategy involved buying stocks where earnings would increase and, in parallel, the market would re-rate the stock with a higher P/E multiple. This dual effect created exponential returns far beyond what earnings growth alone could provide, turning a good investment into a multi-bagger.

Contrary to popular belief, the underlying business fundamentals (sales, profits) of value and growth indexes have grown at nearly the same rate this century. The vast performance gap is not due to better business results but rather investors' willingness to pay increasingly higher multiples for growth stocks.

While the S&P 500's price-to-earnings ratio is near dot-com bubble highs, the quality of its constituent companies has significantly improved. Current companies are more profitable and generate nearly three times more free cash flow than in 2000, providing some justification for today's rich valuations.

High-quality stocks are often expensive, meaning they trade at a high multiple of their earnings. In uncertain times, these multiples can shrink even if the company remains strong, leading to negative returns. Conversely, cheap, low-quality stocks have room for their multiples to expand, delivering positive returns.

Traditional value investing (buying low P/E stocks) is ineffective. Counterintuitively, stocks that recently saw their valuation multiples expand have a higher probability of beating earnings estimates, which is crucial in a market that harshly punishes misses.

The high-yield market's credit quality is at an all-time high, not due to broad economic strength, but because of a massive influx of 'fallen angels.' Downgrades of large, formerly investment-grade companies like Ford and Kraft Heinz have structurally improved the overall quality of the index.