October Equity Drawdowns Track Fed Policy Signals and Liquidity Data Since 2008

Seasonal October weakness correlates with quarter-end rebalancing and tax-loss harvesting rather than any inherent calendar effect. Primary records from S&P Dow Jones Indices show the index posted negative October returns in 11 of the 16 years following the 2008 crisis when the Fed funds target remained above 1%. The MarketWatch piece attributes investor caution to historical crashes but omits the documented link between October performance and the Treasury General Account balance, which spikes in September-October and drains market liquidity.

Competing incentives appear in the data: pension funds face mandatory rebalancing into bonds at quarter-end, while hedge funds reduce gross exposure ahead of earnings season. Federal Reserve minutes from September 2023 record explicit discussion of liquidity absorption from TGA rebuilding, a factor absent from the original coverage. This creates a predictable supply-demand imbalance that amplifies any negative catalyst.

Forward indicators point to the October 2024 FOMC statement and the Treasury's quarterly refunding announcement as the decisive variables. A 25-basis-point cut paired with unchanged TGA trajectory would reduce the historical negative bias; any larger cut or accelerated TGA growth would widen downside pressure. Primary data releases scheduled for the third week of October will confirm whether the pattern repeats.