An analysis article by Moneywise and Yahoo Finance points out that the U.S. stock market currently has three "red flags," and investors should prepare for a potential market crash. As of August 2026, the S&P 500's price-to-earnings ratio has risen to over 30x, the highest level since the dot-com bubble period from late 1998 to late 2002. Additionally, according to data from the Financial Industry Regulatory Authority (FINRA), margin debt surged by approximately 50% in the past year leading up to June 2026, increasing from $1 trillion to $1.5 trillion. The article also mentions that the top ten companies in the S&P 500 (primarily tech giants) currently account for 40% of the index's total market capitalization, a concentration higher than during the tech bubble of the late 1990s. Goldman Sachs expects the S&P 500's annualized return to be only 3% from 2024 to 2034, while Vanguard predicts it to be around 5%.