In this segment from Rule Breaker Investing, Motley Fool co-founder David Gardner gives some thought to what his questioner views as a natural outgrowth of the idea that “winners keep winning.” We can gauge whether a market is “pricey” or over-exuberant based on how price-to-earnings (P/E) ratios generally look compared to historic averages. However, this needs to be seen in the context of interest rates.