Wall Street has been on an incredible run, but some investors are starting to wonder how much further it can go. Could the market be getting ahead of itself? One closely watched valuation measure suggests it’s worth paying attention before assuming the rally will continue without interruption.
Much of today’s excitement comes from artificial intelligence, which has fueled a wave of buying across the technology sector. As a result, the S&P 500‘s Shiller CAPE ratio has climbed to roughly 41.4, putting it close to the highest reading ever recorded outside the dot-com bubble in 2000.
Warning beneath rally
Unlike traditional valuation measures, the Shiller CAPE ratio compares stock prices with companies’ average inflation-adjusted earnings over the past 10 years. That longer view helps smooth out temporary swings in profits, giving investors a better idea of whether stock prices have drifted too far above their underlying earnings. Right now, the reading sits at more than double its long-term historical average.
Reaching that level is especially notable because the market has already weathered plenty of setbacks. Investors looked past the 2023 banking crisis, aggressive Federal Reserve rate hikes, tighter monetary policy, new U.S. tariffs, and even geopolitical tensions that briefly sent oil prices higher. Along the way, the biggest technology companies continued pouring hundreds of billions of dollars into AI chips, data centers, and supporting infrastructure.
When optimism peaked
History offers a useful comparison. During the late 1990s, excitement over the internet sent technology stocks to extreme valuations before the dot-com bubble burst. Although the internet went on to transform the global economy, many companies still paid a heavy price after spending too aggressively.
That does not mean another crash is imminent. Higher valuations, however, leave less room for disappointment if earnings fall short of expectations. Investors may therefore want to review their portfolios, stay diversified, and make sure their investments still align with their long-term goals and risk tolerance.
