The Stock Market Just Did Something for Only the 14th Time in 45 Years -- and It Has a 92% Success Rate of Forecasting the Direction the S&P 500 Will Move Next

The NYSE recently experienced a rare "90/90 day," where over 90% of stocks and 90% of trading volume advanced, marking only the 14th such occurrence since 1980. Historically, this breadth indicator has been a strong bullish signal for the S&P 500, with the index rising in 11 of 12 prior instances (excluding the two this year) and averaging a 23% gain over the subsequent 12 months. While this suggests a positive outlook, the market remains susceptible to macroeconomic headwinds such as persistent inflation, tariff concerns, and Federal Reserve policy, which could contribute to continued volatility.

Analysis

The New York Stock Exchange recently recorded a rare '90/90 day,' a technical signal where over 90% of listed stocks and over 90% of trading volume advanced in a single session. This marks only the 14th such occurrence since 1980, positioning it as a significant market breadth indicator. Historical data from the Carson Group shows this event has a strong bullish precedent for the S&P 500; in 11 of the 12 prior instances, the index was higher one year later, delivering an average gain of 23.2%. This performance notably exceeds the index's long-term average annual return of 8-10%. However, this signal is not infallible, as evidenced by a 23.9% decline following the September 2007 occurrence. The current market context remains defined by high volatility, with the S&P 500 having recently recovered from a 19% plunge to reach new all-time highs. Persistent macroeconomic headwinds, including potential tariffs and ongoing inflation, are explicitly cited as risks that could disrupt this historically positive trend.

Key Decisions for Investors

• Given the strong historical precedent of a '90/90 day' signal, which has preceded an average 12-month S&P 500 gain of 23%, investors could consider maintaining or increasing exposure to broad-market equities.
• Investors should closely monitor key macroeconomic risks cited in the article, specifically inflation data and shifts in the tariff landscape, as these factors could potentially negate the bullish technical signal.
• In light of the expected continued market volatility, employing systematic investment strategies like dollar-cost averaging could be a prudent method for mitigating timing risk while positioning for potential upside.