The Financial Post reports in its Wednesday edition that America's biggest tech companies have become too large even for the stock index tracking them. A Bloomberg dispatch to the Post says that now the benchmark's overseer is taking action to pare back their influence. The seemingly unstoppable growth of megacaps mean they have breached an upper limit imposed on stocks in the Nasdaq 100. As a result, Nasdaq has announced a "special rebalance" will be carried out to redistribute the members. The index provider says the July 24 adjustment will "address overconcentration in the index by redistributing the weights," Nasdaq said. Nasdaq's action is a result of the relentless rally that has accounted for almost all the broader market's gains in 2023. The supercharged performance has sparked a heated debate on Wall Street about whether this top-heavy advance can last. It is "a good thing as it reduces the concentration risk from those players," said Todd Sohn at Strategas Securities. "On the other hand, it increases the burden for the rest of the index to continue to improve and strengthen." On July 3, six companies -- Microsoft, Apple, Alphabet, Nvidia, Amazon and Tesla -- saw their combined weight reach 50.9 per cent.