The Globe and Mail reports in its Saturday edition that there is plenty of talk about how concentrated the U.S. stock market has become, with the top-10 stocks accounting for 31 per cent of the S&P 500 Index. Guest columnist Tom Bradley writes that the Magnificent Seven dominates market talk, comprising Apple, Microsoft, Alphabet, Amazon, Nvidia, Meta and Tesla. While it is hard to believe the Magnificent Seven will ever be dislodged, change is the only consistent pattern around the top 10. If we go back a decade to 2014, the top seven were Apple, Exxon Mobil, Alphabet, Microsoft, Berkshire Hathaway, Johnson & Johnson and Walmart. In 2004, Microsoft was at the top, but the group behind it was quite different: Exxon Mobil, Pfizer, Citigroup, General Electric, Walmart and Intel. Staying at the top of the cap tables is not easy. The math would suggest that the largest cannot continue growing at the pace that got them there, nor can they hold a premium valuation forever. As investors, we need to ensure we are not managing our portfolios while looking in the rearview mirror. Rather, we need to look forward and assess two things: the outlook for a company's profits and sales growth, and the price we are paying for it.