US quantitative funds have just completed a rare position purge. CTA (trend-following quantitative funds) combined holdings plunged from extreme overweight at the end of August to slightly bearish, with a swing exceeding 3 standard deviations within a month — almost unprecedented in recent years. Selling pressure has been released, and potential buying room has opened up substantially.

Meanwhile, US companies have authorized a record $1.3 trillion in buybacks this year, with execution windows reopening progressively from October 15. Position cleansing, buyback ammunition in place, and strong Q4 seasonality in midterm election years — the conditions for a short squeeze are taking shape.

Positions Cleared, Ammunition Ready

According to strategist Rubner's research, the Z-score of CTA holdings (a measure of how far positions deviate from normal) plunged from +2.35 at the end of August to -0.80, falling from extreme bullish to below neutral. After selling pressure was released, the direction of capital flows has already reversed.

Corporate firepower is considerable. Of the $1.3 trillion in authorized buybacks, a large amount of quota is waiting to be executed after the Q3 earnings blackout period ends. Buyback windows open progressively from October 15, and historically corporate buyback intensity typically accelerates further in November.

Seasonality also favors the bulls. According to Rubner's data, since 1930, the S&P 500 has averaged a 5.6% gain in Q4 of midterm election years, nearly double the 2.9% average for Q4 across all years. October and November have historically been the strongest months in midterm election years.

Tech Stocks Refuse to Fall

Under interest rate pressure, the tech sector has shown rare resilience. Nasdaq 100 index futures are approaching the key resistance level of 31,200 points, with the 50-day moving average turning upward again; the Philadelphia Semiconductor Index has broken through short-term resistance and is nearing historically high territory.

The key is AI capital expenditure's low sensitivity to interest rates. According to Goldman Sachs, bond issuance by hyperscale cloud providers (Google, Amazon, etc.) is expected to reach $420 billion by 2027, but interest expenses still account for a very small share of their profits. According to Morgan Stanley, these providers have net leverage of only 0.4x, with cash equivalent to 132% of debt — AI infrastructure has not encountered balance sheet bottlenecks.

There is an asymmetry here: AI spending itself does not depend on low interest rates, but if rates ultimately decline, tech stock valuations will directly benefit — spending does not slow under high rates, and valuations have elasticity when rates are low.

Expectation resets in the semiconductor space provide additional fuel for a short squeeze. According to Goldman Sachs, pricing expectations for traditional memory and HBM (high bandwidth memory) had been significantly downgraded and are now beginning to recover, with more and more investors looking for upside pricing space. JPMorgan noted that semiconductor hardware earnings prospects are solid, TSMC's AI accelerator demand is strong, and advanced process utilization exceeds 100%. Expectation resets, fundamental improvements, technical breakouts — the classic recipe for a short squeeze.

The biggest macro variable in Q4 remains crude oil. According to Goldman Sachs, although global crude oil inventories are above operational minimum levels, the buffer has become significantly thinner, and $100 oil prices are not inconsistent with the current supply-demand balance. The crude oil volatility index (OVX) is currently flat with oil prices below $80, and tail risk may be underpriced.