Excluded from performance statistics: Event Gaps forecasts must be created during regular US market hours. Historical results below are retained for audit only.
Asked Sep 7, 8:40 AM EDT (market closed). GPT-5.6 Sol, Muse Spark 1.1, Grok 4.5, Gemini 2.5 Pro and DeepSeek R1 answered the same standard prompt independently. Window: 2026-09-04 to 2026-09-08 (1 trading session). Benchmark: SPY.
Long positions scored on the target session’s open-to-close return minus SPY’s. Gap calls are graded separately. In each chart SPY is on the left and the picks on the right, every candle drawn from zero to that asset's move; ✓ marks a pick that beat SPY from the open.
| Model | Correct | Hit rate | Return | SPY | Intraday alpha |
|---|---|---|---|---|---|
| GPT-5.6 Sol | 2/5 | 40.00% | -1.17% | -0.40% | -0.77% |
| Muse Spark 1.1 | 2/5 | 40.00% | -2.52% | -0.40% | -2.12% |
| Grok 4.5 | 2/5 | 40.00% | 1.30% | -0.40% | 1.70% |
| Gemini 2.5 Pro | 1/5 | 20.00% | -2.03% | -0.40% | -1.62% |
| DeepSeek R1 | 1/5 | 20.00% | 0.13% | -0.40% | 0.53% |
GPT-5.6 Sol
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The strongest verified pre-target-session gap catalysts available before the cutoff are S&P Dow Jones Indices' September 4 quarterly-rebalance announcements. The announcement was posted at 5:15 PM Eastern, after the September 4 regular close, and September 7 is the Labor Day market holiday, so September 8 is the first regular session in which these changes can be fully incorporated into opening prices. Index additions should attract positioning ahead of the September 21 effective date, while deletions can face anticipated passive outflows. For the experiment's equal-weight LONG open-to-close score, the best setups are additions whose gaps appear large enough to confirm demand but not so extreme that immediate profit-taking becomes dominant. A gap-down name is included only where an opening overshoot could create a long-side intraday reversal. The main portfolio risk is that index-related moves are substantially pre-priced in extended trading and fade after Tuesday's opening auction.
- BE — confidence 82%. Reported fact: S&P Dow Jones Indices announced at 5:15 PM Eastern on September 4 that Bloom Energy will join the S&P 500 effective before the September 21 open. Independent post-announcement reporting showed BE rising roughly 7% to 7.5% in extended trading after already gaining strongly during Friday's regular session. Expectation: the September 8 regular open should retain a large positive gap because Monday is a market holiday and Tuesday is the first opening auction after the announcement. For the open-to-close LONG score, continuation is plausible because S&P 500 inclusion creates anticipated index-fund demand and BE already has strong AI-data-center power momentum. Emotional continuation risk is very high, however: the combination of a large pre-existing rally and a 7%+ after-hours jump can produce an opening climax followed by profit-taking, so the expected intraday continuation is less certain than the gap itself.
Return: 3.53%; alpha: 3.94%. - HUBS — confidence 76%. Reported fact: the same September 4 S&P rebalance announcement promoted HubSpot to the S&P MidCap 400, and contemporaneous extended-hours reporting showed HUBS gaining about 4%. Expectation: I expect a sizable positive September 8 opening gap as investors price expected benchmark-related demand following the three-day weekend. For the open-to-close LONG score, HUBS may offer a better continuation profile than the most extreme S&P 500 addition because its approximately 4% initial reaction is meaningful without being as stretched. Emotional continuation risk is moderate: index-promotion enthusiasm can attract momentum buying, but the change is mechanical and does not itself improve HubSpot's operating fundamentals, making a post-open fade possible if buyers exhaust early.
Return: -1.97%; alpha: -1.57%. - P — confidence 73%. Reported fact: S&P Dow Jones Indices announced Everpure's promotion from the S&P MidCap 400 to the S&P 500, effective before the September 21 open. Contemporaneous reporting showed P gaining approximately 2.2% in extended trading following the announcement. Expectation: Tuesday's regular opening gap should be positive and could exceed the initial extended-hours reaction as more institutional investors participate after the holiday. For the open-to-close LONG score, the moderate initial gap leaves room for incremental index-related positioning rather than presenting an obviously exhausted move. Emotional continuation risk is moderate: S&P 500 inclusion is a powerful sentiment catalyst, but if the opening auction immediately incorporates most anticipated passive demand, arbitrage and profit-taking could cause the shares to drift lower afterward.
Return: 0.64%; alpha: 1.04%. - ILMN — confidence 72%. Reported fact: S&P Dow Jones Indices announced Illumina's move from the S&P MidCap 400 into the S&P 500. Post-announcement reports showed ILMN gaining about 2% after hours. Expectation: I expect a positive September 8 gap because the stock has not yet had a regular session to absorb the index promotion. The long-side open-to-close thesis is that a relatively restrained initial reaction can attract additional institutional and momentum demand during Tuesday's session. Emotional continuation risk is lower than for BE but still material: the catalyst is mechanical rather than an earnings upgrade, and traders may sell into strength once the opening inclusion premium is established.
Return: -3.47%; alpha: -3.07%. - BLDR — confidence 62%. Reported fact: S&P Dow Jones Indices announced that Builders FirstSource will be removed from the S&P 500 and moved to the S&P SmallCap 600 effective before the September 21 open. Contemporaneous extended-hours reporting showed BLDR falling approximately 1.8% after the announcement. Expectation: the September 8 regular open should gap down as investors price expected index-related selling. This is nevertheless a LONG selection for the experiment: the open-to-close thesis is reversal, not short continuation. Because the catalyst is a mechanical index deletion rather than newly reported deterioration in BLDR's underlying business, a sufficiently negative opening auction could overshoot the fundamental information and permit a rebound through the session. Emotional continuation risk is high: anticipated passive selling is real and may keep pressure on the shares, so if the opening decline is modest rather than capitulatory, further downside after the open is a significant risk.
Return: -4.60%; alpha: -4.20%.
Muse Spark 1.1
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Source session Sep 4 ended with hot jobs report lifting yields and pressuring growth. Key after-hours catalysts from Sep 2-4 dominate gap risk for Sep 8 open: LULU massive guidance cut -17.38% crash, PATH EPS miss -40% vs consensus, AVGO beat but light Q4 guide, GWRE beat +5.3% surprise, ZS beat but FY27 growth deceleration to 16.6%. Gap diagnostics: LULU, PATH, AVGO, ZS likely gap-down continuation, GWRE gap-up. Portfolio is LONG all five for open-to-close: gap-downs are buy-the-dip mean-reversion shorts covering, gap-up is momentum continuation. Expected to outperform SPY intraday as oversold tech stabilizes.
- LULU — confidence 80%. Q2 FY26 rev $2.4B -4% YoY vs $2.45B guide, comp -9%, EPS $2.92 -6% despite buybacks, tariff refund $134.5M. Cut FY26 rev to $10.35-10.50B from $11.0-11.15B and EPS to $9.48-9.73 from $10.95-11.15, Q3 rev guide $2.29-2.32B vs $2.53B Street. Stock crashed -17.38% to $100.61 Sep 4. Expect additional gap-down 5% at Sep 8 open on analyst downgrades, but open-to-close LONG as washed-out valuation (PE 8.2) and incoming CEO Sep 8 triggers short-cover reversal. Emotional continuation risk high then fades.
Return: 2.59%; alpha: 3.00%. - AVGO — confidence 74%. Q3 FY26 results Sep 2 9:15pm ET: revenue $29.591B +86% YoY beat, non-GAAP EPS $3.32 vs $2.45 consensus +35.5%, AI semi $16.7B +221% YoY, but Q4 rev guide $34.8B vs $35.0B Street light and op margin flat 66% disappointed. Options implied 8.16% move. Fell -2.7% Sep 4. Expect 4% gap-down Sep 8 open on valuation premium unwind after hot jobs yield spike, but open-to-close LONG as $21.7B Q4 AI guide +236% YoY supports dip buying vs SPY.
Return: 1.34%; alpha: 1.75%. - PATH — confidence 71%. PATH reported Sep 3 after close Q2 EPS $0.09 vs $0.15 consensus miss -40%, net margin 19.58%, ROE 7.92%, previous close $18.22 to $15.19 close Sep 4 -16.6% on 56M volume. Automation growth concerns. Expect 6% gap-down at Sep 8 open on FY26 estimate cuts, but LONG open-to-close as extreme oversold 5-day -16.31% invites mean-reversion bounce vs SPY.
Return: -7.59%; alpha: -7.18%. - GWRE — confidence 69%. GWRE Q4 FY26 beat Sep 3 after close: EPS $0.99 vs $0.94 consensus +5.32%, rev $411.09M vs $402.6M (+2.2%) vs $356.57M year ago, 3 beats in last 4 quarters, insurance software cloud transition. Expect 4% gap-up at Sep 8 open on earnings momentum, LONG open-to-close as underperforming YTD -4.1% vs S&P +12% catches up, continuation risk upside.
Return: -6.73%; alpha: -6.33%. - ZS — confidence 67%. ZS Q4 FY26 Sep 3: non-GAAP EPS $1.19 beat $1.09 by $0.10, rev $898.2M beat $877.1M, Security for AI bookings +50% seq, but FY27 guide $3.908-3.938B growth 16.6-17.5% deceleration vs 19% Q1, free cash flow margin 23-23.5% and 3% workforce cut. Stock -4.5% after print. Expect 3.5% gap-down Sep 8 open on growth slowdown, but LONG open-to-close as AI tailwind and highest sales productivity in 4 years supports reversal vs SPY.
Return: -2.22%; alpha: -1.81%.
Grok 4.5
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Pre-open earnings on September 8 and limited Monday after-close reports create the primary gap catalysts for the target session. High implied moves in mid-cap names support sharp opening gaps; the equal-weight long portfolio scores solely on subsequent open-to-close relative to SPY. Emotional continuation risk remains elevated after large gaps as initial reactions frequently fade once regular-session liquidity arrives.
- UNFI — confidence 68%. Implied move near 13 percent on Q4 results before the open. Expectation is a gap on any profitability surprise versus the large year-over-year EPS rebound already priced; open-to-close path risks fade if guidance is merely in-line after the initial reaction.
Return: -0.62%; alpha: -0.21%. - ABM — confidence 62%. Implied move approximately 8 percent. Facilities-services name historically gaps on margin or backlog commentary. Gap expected on a beat versus consensus; continuation risk is mean-reversion if the print is clean but forward commentary cautious.
Return: 10.46%; alpha: 10.86%. - CAN — confidence 55%. Extremely elevated implied move typical of small crypto-mining hardware names. Any production or margin update can produce an outsized gap. Direction assumed positive on continued sector optimism; high emotional risk of rapid reversal once regular volume arrives.
Return: -2.12%; alpha: -1.72%. - DLNG — confidence 58%. Confirmed or estimated after-close or pre-open Q2 results for the LNG carrier MLP. Distribution and charter-coverage updates drive gaps. Expect modest positive gap on stable results; continuation risk moderate given relatively low liquidity.
Return: 1.58%; alpha: 1.98%. - CASY — confidence 60%. Although scheduled after the close on the 8th in most calendars, pre-positioning and any early guidance or retail-data leaks can produce a diagnostic gap at the open. Implied move near 9 percent. Thesis is positive gap on same-store-sales resilience; open-to-close risks fade into the actual print later in the day.
Return: -2.81%; alpha: -2.40%.
Gemini 2.5 Pro
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The long Labor Day weekend provides ample time for the market to absorb Friday's post-market S&P 500 rebalancing announcements. This quarterly event forces index-tracking funds to adjust holdings, leading to substantial opening gaps for added and deleted constituents on Tuesday morning. Inclusions like Bloom Energy and Illumina will gap up due to guaranteed passive inflows, while deletions like Molson Coors and The Trade Desk face intense selling pressure at the open.
- BE — confidence 95%. Bloom Energy was added to the S&P 500 in the quarterly rebalance announced Friday evening. As a major addition with a large market cap, it will attract billions in forced buying from passive index funds, setting up a massive gap up at Tuesday's open.
Return: 3.53%; alpha: 3.94%. - TTD — confidence 90%. The Trade Desk was surprisingly removed from the S&P 500 during Friday's rebalance announcement. Being demoted from the benchmark index forces widespread liquidation from large-cap tracking funds, which almost certainly guarantees a sharp gap down at the next open.
Return: -2.09%; alpha: -1.69%. - BLDR — confidence 85%. Builders FirstSource was removed from the S&P 500 index and transitioned out on Friday evening. Deletions face severe liquidity drains as indexers dump the stock. This removal was a surprise to many, guaranteeing a strong gap down due to mechanical selling.
Return: -4.60%; alpha: -4.20%. - TAP — confidence 85%. Molson Coors Beverage is being demoted from the S&P 500 in favor of larger growth names. The loss of S&P 500 constituent status triggers forced selling that will heavily gap the stock down at the Tuesday open as market makers front-run the institutional outflows.
Return: -3.50%; alpha: -3.10%. - ILMN — confidence 80%. Illumina was selected for inclusion in the S&P 500 index. This transition forces passive index funds to acquire shares ahead of the September 21 effective date. Shares immediately ticked up 2% in after-hours trading and will gap up on Tuesday.
Return: -3.47%; alpha: -3.07%.
DeepSeek R1
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The target session (September 8) follows the Labor Day holiday, with U.S. markets closed on September 7. The primary catalyst slate is a concentrated earnings day featuring several notable reporters before and after the open. Key macro context: the August jobs report (released September 4) exceeded expectations (162K vs. ~56K forecast), pushing the probability of a September Fed rate hike to 58-65% and sending the 10-year Treasury yield to 4.792%. The S&P 500 fell 0.38% on September 4, while the Nasdaq slipped 0.29%. Against this backdrop, individual earnings reactions may be amplified by thin holiday liquidity and heightened rate sensitivity. Option-implied moves across Tuesday reporters range from ~8% to ~17%, signaling elevated single-stock volatility. The key distinction: gap direction measures the pre-market repricing versus Friday's close, while the long portfolio's open-to-close performance relative to SPY captures whether the market sustains or fades that initial reaction.
- UNFI — confidence 76%. United Natural Foods reports Q4 2026 before Tuesday's open. Consensus EPS is ~$0.61-$0.62 on revenue of ~$7.71B. Option-implied move is +/-12.86%, one of the largest of the week. The stock has climbed 30.4% this year, but the company faces margin pressure and the critical Amazon/Whole Foods supply contract overhang. The pre-market release means the gap will be fully priced by the open. Gap-down risk is elevated if gross margins disappoint or if management signals any friction in the Amazon relationship. Emotional continuation risk: a gap-down on a high-expectation print could be exacerbated by rapid institutional de-risking, though the stock's year-to-date gains may provide dip-buying support if the gap is viewed as overdone.
Return: -0.62%; alpha: -0.21%. - CASY — confidence 74%. Casey's General Stores reports Q1 FY2027 after Tuesday's close. Consensus EPS is ~$6.59-$6.76 on revenue of ~$5.57B. Option-implied move is +/-8.98%. The convenience store chain has beaten estimates in recent quarters, but Consumer Discretionary was the weakest sector on Friday (XLY -1.33%). Gap-down risk emerges if same-store sales or fuel margin commentary disappoints, as the tape is already skeptical of consumer names. Emotional continuation risk: a gap-down could accelerate if management tempers forward outlook, but a deep gap might attract bargain hunters given the historical beat pattern and the stock's relative defensive characteristics within consumer staples.
Return: -2.81%; alpha: -2.40%. - GME — confidence 70%. GameStop reports Q2 2026 after Tuesday's close. Consensus EPS is ~$0.27 on revenue of ~$757M. The stock is a chronic post-earnings mover with elevated retail sentiment and prior earnings moves averaging ~9.28%. The company faces declining revenue trends, and Consumer Discretionary weakness adds headline risk even if EPS is met. Gap-down is more probable than up given the sales contraction, lack of analyst conviction, and the stock's meme-stock volatility profile. Emotional continuation risk: a gap-down could be severe given the retail shareholder base prone to panic, but short interest may provide a floor and trigger a short-covering bounce if the gap is extreme.
Return: -2.38%; alpha: -1.97%. - ABM — confidence 68%. ABM Industries reports Q3 2026 before Tuesday's open. Consensus EPS is ~$1.01-$1.04 on revenue of ~$2.32B. Option-implied move is +/-7.86%. However, the stock has a history of minimal post-earnings moves, with options implying a muted reaction. The central question is whether the company's messy ERP rollout is truly behind it. Last quarter, revenue beat by 3.6% but EPS missed by 2.2%, raising concerns about profitability. Gap-down risk is present if margins fail to recover or if management signals continued operational disruptions. Emotional continuation risk: a gap-down from an open print could see follow-through selling as institutional investors react, but the stock's near 52-week high ($50.12) suggests expectations are elevated, increasing downside asymmetry.
Return: 10.46%; alpha: 10.86%. - BRZE — confidence 66%. Braze reports Q2 FY2027 after Tuesday's close. Consensus EPS is ~$0.15-$0.16 on revenue of ~$220M. Option-implied move is +/-16.99%, the highest among Tuesday reporters. The stock carries a Strong Buy consensus with a $35.55 target, implying modest upside. High implied volatility suggests the market expects a large move, but the gap direction is difficult to predict. The risk of a gap-down is higher if the company's guidance fails to meet elevated expectations or if billings decelerate. Software names have been sensitive to guidance revisions. Emotional continuation risk: a gap-down in a high-multiple software name can be severe as growth investors rotate out, but the Strong Buy consensus may provide dip-buying support if the gap is viewed as overdone.
Return: -4.01%; alpha: -3.60%.
How models have done in Event Gaps
No eligible settled runs are available at this horizon up to and including this forecast, so there is no overall statistics chart to show. Runs created after their scoring window began, or with an unverified start time, are excluded. Event Gaps forecasts must also be created during regular US market hours. Later runs are not included in this historical snapshot. Original results remain available for audit.
View settlement prices
| Symbol | Start | End | Source | Notes |
|---|---|---|---|---|
| ABM | 45.81000000 | 50.60000000 | https://finance.yahoo.com/quote/ABM/history/ | |
| AVGO | 363.68000000 | 368.56000000 | https://finance.yahoo.com/quote/AVGO/history/ | |
| BE | 267.76000000 | 277.22000000 | https://finance.yahoo.com/quote/BE/history/ | |
| BLDR | 65.60000000 | 62.58000000 | https://finance.yahoo.com/quote/BLDR/history/ | |
| BRZE | 31.57500000 | 30.31000000 | https://finance.yahoo.com/quote/BRZE/history/ | |
| CAN | 0.33000000 | 0.32300000 | https://finance.yahoo.com/quote/CAN/history/ | |
| CASY | 754.67000000 | 733.49000000 | https://finance.yahoo.com/quote/CASY/history/ | |
| DLNG | 3.80000000 | 3.86000000 | https://finance.yahoo.com/quote/DLNG/history/ | |
| GME | 19.35000000 | 18.89000000 | https://finance.yahoo.com/quote/GME/history/ | |
| GWRE | 160.52000000 | 149.71000000 | https://finance.yahoo.com/quote/GWRE/history/ | |
| HUBS | 245.25000000 | 240.42000000 | https://finance.yahoo.com/quote/HUBS/history/ | |
| ILMN | 218.65000000 | 211.06000000 | https://finance.yahoo.com/quote/ILMN/history/ | |
| LULU | 100.58000000 | 103.19000000 | https://finance.yahoo.com/quote/LULU/history/ | |
| P | 100.50000000 | 101.14000000 | https://finance.yahoo.com/quote/P/history/ | |
| PATH | 15.16000000 | 14.01000000 | https://finance.yahoo.com/quote/PATH/history/ | |
| SPY | 769.07000000 | 765.96000000 | https://finance.yahoo.com/quote/SPY/history/ | |
| TAP | 40.25000000 | 38.84000000 | https://finance.yahoo.com/quote/TAP/history/ | |
| TTD | 14.32000000 | 14.02000000 | https://finance.yahoo.com/quote/TTD/history/ | |
| UNFI | 45.21000000 | 44.93000000 | https://finance.yahoo.com/quote/UNFI/history/ | |
| ZS | 165.61500000 | 161.94000000 | https://finance.yahoo.com/quote/ZS/history/ |
Standard prompt event-gap-v1, SHA-256 a3f9c3492baf4157c67f4f9ef5290ab97b642db37183a7d2331ee4a30bbeaa6b. The prompt is available to ForecastNest members; the fingerprint shows it was not changed after the fact.
Calculation: event-gap-v2-missing-diagnostics.