SPY 1-day forecast by Claude Sonnet 4.5
Claude Sonnet 4.5's 1-day forecast for SPY, made 2026-09-22: expected range $768.00 to $781.00 at 55% confidence. Settled at $769.72: direction called incorrectly, score 31.4.
| Asset | SPY |
|---|---|
| Model | Claude Sonnet 4.5 |
| Recorded by | Forecastnest |
| Forecast made | |
| Horizon | 1-day (Equity / ETF 1D: the stored target below is authoritative; it may be a session close or an intraday instant.) |
| Window closes | |
| Price when asked | $773.48 |
| Price the model reported | $773.50 |
| Expected range | $768.00 to $781.00 |
| Confidence | 55% |
| Prompt style | No data |
| Status | Settled |
| Actual close | $769.72 |
| Traded range in the window | $768.37 to $774.94 |
| Result | Direction called incorrectly |
| Score | 31.4 of 100 |
The model's reasoning
(1) What I found: SPY closed at $773.50 on Sept 21, up 1.55%, with the S&P 500 at 7,764.70, within 0.4% of its record close (CMoney, Benzinga, Saxo). VIX fell to 14.69, its lowest since Sept 3 (MarketWatch). The 10-year Treasury yield sits near 4.95% (TradingEconomics, Yonhap Infomax). Brent crude is around $100 but pulled back from session highs (Algerian Radio, VOV).
(2) Market regime: A low-volatility bull market with a hawkish Fed overlay. The FOMC hiked rates 25bp to 3.75%-4.00% on Sept 16 (JPMorgan, Investing.com). Market breadth is deteriorating: more S&P 500 constituents hit 52-week lows than highs on Sept 21, a divergence last seen in 1999 (SentimenTrader via Edgen). Less than 30% of S&P 500 stocks are above their 50-day moving average (Entrust via CMoney).
(3) Price range: SPY sits just below the $775 resistance zone that has capped two weeks of rallies (KuCoin, eToro). Support is at $767-770, with stronger structural support at $760-762 (Investing.com, KuCoin). With VIX at 14.69, a one-day expected move implies roughly $768-$781. I have given slightly more room above than below because momentum and options positioning (dealer gamma positive, call wall at $785) lean supportive for a single session.
(4) Catalysts: No major economic data scheduled for Sept 22. Fed speakers could add hawkish commentary following the Sept 16 hike. Oil price action remains a wildcard given Middle East tensions and the Treasury's announced shutdown of Iranian airlines. Minor earnings (AutoZone, KB Home, Thor Industries) are unlikely to move the index.
(5) Counter-argument: The breadth divergence and hawkish Fed are genuine warnings. If SPY loses $767, sellers could press toward $761 and the bearish triple-witching pattern becomes relevant (Investing.com). A sustained break above $775 would invalidate the near-term cautious tilt and open $780-$785.
(6) Confidence: 55% - moderate. The price momentum is strong but internal breadth is poor, making a one-day directional call genuinely uncertain. I lean neutral on the session and slightly cautious over the coming week.
Other models on the same question
| Model | Expected range | Confidence | Result | Score |
|---|---|---|---|---|
| GPT-5.6 Sol | $767.50 to $783.50 | 57% | Direction called incorrectly | 31.3 |
| Claude Opus 5 | $767.00 to $780.00 | 30% | No directional call | 53.1 |
| Muse Spark 1.1 | $760.00 to $771.00 | 56% | No directional call | 50.7 |
| Gemini 1.5 Pro | $768.00 to $780.00 | 65% | No directional call | 54.8 |
| Grok 4.5 | $769.00 to $778.50 | 45% | No directional call | 54.1 |
How this forecast is measured
Sends only the baseline price and the output format; your AI researches the asset itself. Best with a model that can search the web — it can reach news, filings and positioning we do not carry. Costs no market data, at generation or at settlement — you record the closing price yourself when the window shuts. The monthly allowance is what a membership buys, not a data bill.
Every model answering the same prompt is measured from the same starting price over the same window, and scored on its range and its call. How scoring works · All shared research.
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