Event Gaps: Claude Opus 5.5's picks for 2026-09-28
Claude Opus 5.5 picked MTN, NVDA, JEF, MU, SPCX for a 1-day horizon. Intraday alpha vs SPY: +0.91%. Picks with positive alpha: 60%.
| Experiment | Event Gaps |
|---|---|
| Model | Claude Opus 5.5 |
| Prompt version | event-gap-v10 |
| Asked | |
| Horizon | 1-day |
| Measured from | 2026-09-28 |
| Measured to | 2026-09-29 |
| Benchmark | SPY |
| Status | Settled |
| Intraday alpha vs SPY | +0.91% |
| Picks with positive alpha | 60% |
| Benchmark return | -0.27% |
The picks
| Rank | Symbol | Gap direction | Price change | Return in the called direction | Confidence | vs benchmark | Called right |
|---|---|---|---|---|---|---|---|
| 1 | MTN | -1.87% | +1.87% | 55% | +2.14% | Yes | |
| 2 | NVDA | -0.58% | -0.58% | 55% | -0.31% | No | |
| 3 | JEF | +0.01% | +0.01% | 52% | +0.28% | Yes | |
| 4 | MU | +2.71% | +2.71% | 50% | +2.98% | Yes | |
| 5 | SPCX | -0.84% | -0.84% | 45% | -0.57% | No |
The model's market view
Risk-off Monday open. The S&P 500 is down about 0.5% and the Nasdaq underperforms after Trump rejected Iran's truce proposal (Brent near $107-108), the 10-year yield sits near 5.2%, and fresh AI-safety incidents weigh on software and chips. Against this tape, the most tradeable single-stock catalysts inside the window are: two after-close earnings reports tonight (Jefferies and Vail Resorts, both officially scheduled), NVIDIA's record buyback increase (observed this morning), Micron's pre-earnings positioning ahead of its confirmed Sept 30 report (outside the window, so anticipation only), and SpaceX's Starship Flight 14 (launched this morning, with the orbital phase still pending). Directional calls are made from the price at submission, not from the opening gap. Continuation risk is high in NVDA and SPCX, where part of the news is already priced.
Why each pick
MTN
Thesis (down): Vail reports FY2026 Q4 after today's close. The setup skews negative. The Q4 EPS consensus has been drifting lower. Vail missed estimates in three of the last four quarters, including a miss on both EPS and revenue in the peak winter quarter. Reports flag mounting concerns over declining Epic Pass sales after a poor-snowfall season with lower skier visits. With consumer sentiment near historic lows and the dividend payout ratio around 171%, weak pass units or soft FY2027 guidance could trigger a gap down at tomorrow's open, inside the window. Expectations versus facts: all of this is anticipated, and no results have been reported yet. Risks: expectations are already low, and 13 analysts are neutral with a mean target about 6% above the current price. The $106M annualized cost-savings program, strong Australian pass growth or a dividend reaffirmation could produce a relief rally, and a clean beat would squeeze bears. Price note: reference_price is an intraday Sept 28 quote cited by Investing.com (Reuters) shortly before submission, not an exchange feed.
NVDA
Thesis (up): observed fact. This morning NVIDIA's board added $150B to its repurchase authorization, the largest increase on record, bringing the remaining authorization to $235B through FY2028. It also launched an open agent-safety platform aimed directly at the AI-containment incidents that are pressuring the sector. The stock traded roughly 3% higher near the open while the Nasdaq fell, showing idiosyncratic demand. Reported forward P/E of about 16.5x (a decade low) invites follow-through buying and analyst reiterations into tomorrow morning. I forecast only a modest further gain from the current, already-elevated level. Risks: emotional continuation may fade, since opening gaps on buyback news often partially retrace. The semiconductor group is under pressure (OpenAI training pause, SK Hynix and KOSPI weakness, AMD and Broadcom slipping), and beta of about 2.2 means a deeper Nasdaq selloff could drag NVDA lower despite the buyback. Price note: I could not retrieve a clean live intraday print, so reference_price is the last regular-session close (Sept 25) from the Yahoo quote page; reports put intraday trading around +3.4%.
JEF
Thesis (up): Jefferies reports fiscal Q3 (June-August) after today's close. Consensus is roughly $1.00 EPS on about $2.2B revenue. EPS estimates were revised up about 8% over the past month, consistent with a strong summer for IPOs and underwriting (including mega-IPO activity) and active trading desks in a volatile rate and oil tape. As an early bellwether for bank capital-markets revenue, a beat could lift the stock at tomorrow's open. Valuation support: GuruFocus flags a discount to its GF Value, and insiders have been net buyers. Expectations versus facts: estimate revisions are observed, while the results themselves are not yet reported. Risks: Jefferies missed in the prior quarter. It has elevated leverage (debt-to-equity around 3.5), and credit or private-credit marks or trading losses tied to the rate spike could disappoint. Higher estimates also raise the bar, so a merely in-line print could sell off. Price note: reference_price is the last close cited by GuruFocus (most recent regular session, Sept 25); I could not obtain a Sept 28 intraday quote.
MU
Thesis (up): Micron's confirmed FQ4 report on Sept 30 after the close falls outside this window, so the trade is pre-earnings anticipation. Consensus looks for record revenue of about $51B (+353% YoY). Wells Fargo ($1,525) and Citi ($1,300) raised targets last week, retail sentiment is strongly bullish, and traders are positioning for a possible new buyback. The stock has rebounded about 17% from its Sept 16 low to $1,082. Today's chip-wide dip on AI-safety headlines and SK Hynix weakness could be bought as positioning builds into the print. Risks: the rally has been extreme (+275% YTD) and the setup is crowded. The OpenAI training pause and 'chips with nowhere to go' narratives could deepen memory-stock selling. Solidigm IPO chatter and the KOSPI's 2.7% drop show that Asian memory peers are weak today, and pre-earnings de-risking is possible. Price note: reference_price is the Sept 25 close cited by TradingKey (most recent regular session); I found no Sept 28 intraday quote, though Stocktwits reported about a 1% overnight dip.
SPCX
Thesis (up): Starship Flight 14, the vehicle's first orbital attempt carrying 26 Starlink V3 satellites, launched this morning. The company's update (reported by GuruFocus) confirmed hot-staging with Raptor ignition, a controlled Super Heavy splashdown and a completed ascent burn, with the orbital phase planned later today. If orbit and satellite deployment are confirmed later in the session, the key Starlink-scaling milestone could push the stock through the $153-153.50 resistance flagged by analysts, and success headlines typically extend into the next morning. The stock is also about 27% below its 52-week high, leaving room for a relief move. Observed versus uncertain: launch and ascent occurred; orbital insertion and deployment are not yet confirmed. Risks: this is a binary outcome, so an anomaly in the orbital phase would likely cause a sharp drop. Sell-the-news, an approaching lockup expiry, recent insider sales (including by the President) and a price-to-sales multiple above 150x all cap the upside. Price note: reference_price is the Sept 28 pre-market quote reported by TheStreet, not a regular-session print.
Other models on the same run
| Model | Picks | Intraday alpha vs SPY | Picks with positive alpha |
|---|---|---|---|
| Perplexity | KOD, SPCX, IDT, MTN, GNS | +0.03% | 40% |
| Gemini 1.5 Pro | RBLX, NVDA, PEP, RLJ, COST | +0.63% | 60% |
| Grok 4.5 | NVDA, JEF, CCL, MU, NKE | +3.07% | 80% |
| GPT-6 | MDB, KOD, BA, MU, BWXT | -0.55% | 40% |
| DeepSeek | JEF, CCL, KMX, SRRK, TSLA | +3.51% | 60% |
| Muse Spark 1.1 | JEF, CCL, KMX, AIR, CNXC | -1.69% | 60% |
Written up on ForecastNest Insights: Event Gaps: Claude Opus 5.5's picks for 2026-09-28.
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