Risk-reward outlook for stocks is getting worse as historically tough month kicks off, says Citadel

• The S&P 500 hit an all-time intraday high of 7,816.70 in August, but volatility has since compressed to year-to-date lows, making protective options relatively inexpensive
• September faces multiple headwinds: historically the weakest month for stocks, reduced retail buying activity (about half the average since 2019), and corporate buyback blackout periods
• Single-stock volatility premiums have compressed significantly following strong tech earnings like Nvidia, with the spread between Nasdaq 100 and SPY volatility falling to the lowest 20th percentile in a year

Summary

Key Message: Citadel Securities warns that the near-term risk-reward outlook for U.S. equities is deteriorating as September begins, despite maintaining a constructive longer-term view.

Main Points:

Scott Rubner, Citadel Securities' head of equity and equity derivatives strategy, identifies several factors creating unfavorable near-term asymmetry:

• September is historically the worst month for stocks
• Volatility Index (VIX) hit 2026's lowest level at 14.1 last week, making options protection the cheapest all year
• The S&P 500 reached an all-time intraday high of 7,816.70 this month after gaining nearly 7% from late July through early August, but has since drifted sideways

Key Market Dynamics:

• Single-stock volatility relative to index volatility has compressed from record highs, particularly following strong tech earnings like Nvidia's recent report
• The spread between Nasdaq 100 and SPY volatility fell from June's all-time high to the lowest 20th percentile in a year
• Corporate buyback activity will slow due to blackout periods ahead of earnings reports

Behavioral Factors:

Since 2019, retail net buying during down days in September averages about half the typical rate, reducing a key support mechanism for markets.

Investment Implication:

Rubner recommends purchasing downside protection, noting that "investors are entering a much more macro event-heavy period while paying relatively little premium for protection." The convergence of seasonal weakness, reduced buyback support, muted retail participation, and cheap volatility creates a compelling case for hedging equity exposure in the near term.