S&P 500 CAPE RATIO: Be Careful!S&P 500 IndexTVC:SPXSwissquoteMany investors are concerned about the long-term trend of the S&P 500 index, which has been firmly bullish since the end of 2022. But what exactly is a strong bullish trend? It is a market dynamic that alternates between bullish rallies (sometimes nearly vertical) and correction phases whose time horizon remains limited to the short term (a few trading sessions, sometimes a few weeks). Ultimately, after each short-term correction, the underlying bullish trend reasserts itself. "A trend resumes many times, but reverses only once." I, Vincent Ganne, coined this expression, and it means that as long as the fundamentals remain supportive, a long-term bullish trend will eventually resume. (Follow the Swissquote account on TradingView to read my daily market analysis.) BUT there will come a time when the stock market becomes excessively expensive. Even if forward-looking fundamentals remain excellent, an overvalued market can reverse into a decline lasting several months. Just remember the bear market of 2022. Among all valuation indicators, one of the most closely monitored by institutional traders is approaching its all-time high. That historical peak (set in 1999) could act as resistance and halt the long-term bullish trend. This valuation indicator is the Shiller P/E, also known as the CAPE Ratio. What does it measure? The charts below show the S&P 500 Shiller P/E, both in its standard version (top) and normalized version (bottom). The CAPE Ratio (Cyclically Adjusted Price-to-Earnings) compares the level of the S&P 500 with the inflation-adjusted average earnings of its constituent companies over the past ten years. Unlike the traditional P/E ratio, it smooths out business cycle fluctuations and provides a long-term view of U.S. equity market valuations. Historically, when the CAPE Ratio reaches extreme levels, stock market returns over the following years tend to be less favorable. This does not mean that a crash is imminent, but rather that upside potential gradually becomes more limited while the risk of a deep correction increases. Today, the CAPE Ratio is trading close to its all-time high reached during the 1999-2000 dot-com bubble. At the same time, its normalized Z-Score, which measures how far valuations deviate from their historical average, is also approaching a level of excess rarely seen over the past fifty years. This should not be viewed as a sell signal on its own. Markets can remain overvalued for extended periods when corporate earnings continue to grow, liquidity remains abundant, and investors continue to favor equities. Nevertheless, it is an important warning: at the first sign of economic slowdown, disappointing earnings, or a monetary policy shock, the market's margin of safety becomes extremely thin. DISCLAIMER: This content is intended for individuals who are familiar with financial markets and instruments and is for information purposes only. The presented idea (including market commentary, market data and observations) is not a work product of any research department of Swissquote or its affiliates. This material is intended to highlight market action and does not constitute investment, legal or tax advice. If you are a retail investor or lack experience in trading complex financial products, it is advisable to seek professional advice from licensed advisor before making any financial decisions. This content is not intended to manipulate the market or encourage any specific financial behavior. Swissquote makes no representation or warranty as to the quality, completeness, accuracy, comprehensiveness or non-infringement of such content. The views expressed are those of the consultant and are provided for educational purposes only. Any information provided relating to a product or market should not be construed as recommending an investment strategy or transaction. Past performance is not a guarantee of future results. Swissquote and its employees and representatives shall in no event be held liable for any damages or losses arising directly or indirectly from decisions made on the basis of this content. The use of any third-party brands or trademarks is for information only and does not imply endorsement by Swissquote, or that the trademark owner has authorised Swissquote to promote its products or services. Swissquote is the marketing brand for the activities of Swissquote Bank Ltd (Switzerland) regulated by FINMA, Swissquote Capital Markets Limited regulated by CySEC (Cyprus), Swissquote Bank Europe SA (Luxembourg) regulated by the CSSF, Swissquote Ltd (UK) regulated by the FCA, Swissquote Financial Services (Malta) Ltd regulated by the Malta Financial Services Authority, Swissquote MEA Ltd. (UAE) regulated by the Dubai Financial Services Authority, Swissquote Pte Ltd (Singapore) regulated by the Monetary Authority of Singapore, Swissquote Asia Limited (Hong Kong) licensed by the Hong Kong Securities and Futures Commission (SFC) and Swissquote South Africa (Pty) Ltd supervised by the FSCA. Products and services of Swissquote are only intended for those permitted to receive them under local law. All investments carry a degree of risk. The risk of loss in trading or holding financial instruments can be substantial. The value of financial instruments, including but not limited to stocks, bonds, cryptocurrencies, and other assets, can fluctuate both upwards and downwards. There is a significant risk of financial loss when buying, selling, holding, staking, or investing in these instruments. SQBE makes no recommendations regarding any specific investment, transaction, or the use of any particular investment strategy. CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. The vast majority of retail client accounts suffer capital losses when trading in CFDs. You should consider whether you understand how CFDs work and whether you can afford to take the high risk of losing your money. Digital Assets are unregulated in most countries and consumer protection rules may not apply. As highly volatile speculative investments, Digital Assets are not suitable for investors without a high-risk tolerance. Make sure you understand each Digital Asset before you trade. Cryptocurrencies are not considered legal tender in some jurisdictions and are subject to regulatory uncertainties. The use of Internet-based systems can involve high risks, including, but not limited to, fraud, cyber-attacks, network and communication failures, as well as identity theft and phishing attacks related to crypto-assets.