
Over the past six months, the S&P 500 has staged an incredible rally—one that was very much in line with what my models had projected earlier this year. Back at the start of 2025, following the tariff tantrum and the heavy selloff, we flagged the market’s move as a clear mispricing. Flows were simply too strong to justify the decline, and sure enough, the rebound has been powerful.
But as we head into October, the winds that fueled this rally are beginning to shift. What were tailwinds over the summer are now turning into headwinds. The key message I want to make clear is this: I believe we’re at an inflection point, and volatility is likely to spike in the near term. The rally looks exhausted, and a breather—possibly a sharp one—is overdue.
The First Domino: Treasury Flows and the Tax Drain
The most important factor right now comes down to fiscal flows. The daily Treasury statement is, in many ways, the first mover of macroeconomic outcomes.
Each September, we see a major corporate tax drain. This year, starting around September 11th, roughly $120 billion was pulled out of the private sector over a two-week period. On its own, that may not change the long-term trajectory of the economy—but in the short run, it significantly pressures the balance sheet capacity of the financial sector.