The Globe and Mail reports in its Saturday edition that there are nearly 60,000 listed companies around the world, but only seven that really matter. The Globe's Tim Shufelt writes that mega-cap U.S. tech stocks have assumed planet-like proportions around which all other global equities orbit. Known as the magnificent seven -- Apple, Microsoft, Alphabet, Amazon, Nvidia, Meta and Tesla -- this group has grown in market capitalization by $4.7-trillion (U.S.) this year alone. Chances are, your own financial well-being has some level of vulnerability to the magnificent seven stocks. Their share of the S&P 500 Index has risen to nearly 30 per cent. Should everyday investors change how they invest in U.S. stocks? On the surface, the S&P 500 is having a rebound year after a sound trouncing in 2022. However, the index's year-to-date advance of 19 per cent owes a lot to the magnificent seven. Remove those seven stocks and the gain on the year shrinks to 6 per cent. It is generally considered a good thing to have a larger number of companies contributing to index gains. Conventional market wisdom holds that market rallies with narrow leadership are fragile creatures, prone to vanishing at the slightest provocation.