Stock Selection: Claude Opus 5.5's picks for 2026-11-03
Claude Opus 5.5 picked FISV, IDXX, HWM, RVTY, FN for a 1-day horizon. Portfolio return vs SPY: -3.75%. Picks that beat SPY: 40%.
| Experiment | Stock Selection |
|---|---|
| Model | Claude Opus 5.5 |
| Prompt version | stock-selection-v8 |
| Asked | |
| Horizon | 1-day |
| Measured from | 2026-11-03 |
| Measured to | 2026-11-04 |
| Benchmark | SPY |
| Status | Settled |
| Portfolio return vs SPY | -3.75% |
| Picks that beat SPY | 40% |
| Benchmark return | +1.19% |
The picks
| Rank | Symbol | Return | Confidence | vs benchmark | Called right |
|---|---|---|---|---|---|
| 1 | FISV | +5.78% | 57% | +4.59% | Yes |
| 2 | IDXX | +3.56% | 56% | +2.37% | Yes |
| 3 | HWM | -7.85% | 55% | -9.04% | No |
| 4 | RVTY | -6.60% | 53% | -7.79% | No |
| 5 | FN | -7.68% | 52% | -8.87% | No |
The model's market view
The market is mixed at midday on Election Day, 2026-11-03. By mid-morning the S&P 500 was up about 0.4% and the Nasdaq about 0.8% (Investrade), as chip stocks rebounded and oil fell on US-Iran diplomacy hopes. The Dow was lower on Apple's margin-driven drop. Equal-weight and rotation trades have been outperforming mega-cap tech, and Schwab notes that 61% of S&P 500 members are back above their 50-day averages. Two binary events fall inside the window, which ends at 11:26 ET on Nov 4: AMD and Arm earnings after today's close, and the midterm results overnight. Those add gap risk at the Nov 4 open, mostly concentrated in AI and semiconductor names. I favour mid- and large-cap stocks outside mega-cap tech with fresh beat-and-raise or capital-return catalysts, where analyst estimate revisions and buybacks tend to keep the move going. Equal-weight long-only picks, benchmarked against SPY.
Why each pick
FISV
Thesis: Fiserv delivered a better-than-feared Q3 before today's open:
- Adjusted EPS of $1.75 vs $1.72 consensus, and revenue above estimates.
- 2026 EPS guidance of $7.20-7.40 reaffirmed.
- Project Elevate savings target doubled to $1B from $500M, with headcount down by 3,000 since June.
- Buybacks resume early, with $500M planned for Q4 (Benzinga, Investing.com, Investrade).
The stock was up 11.05% at 11:02 ET (StockTitan), a move from a heavily de-rated base: about 10x trailing earnings and well below its $70.41 52-week high. Mechanical support should carry into the next session: a buyback of about 1.7% of the market cap, cost-driven upward revisions to 2027 EPS, and activist pressure (Jana Partners has urged a sale, and Michael Burry has floated a $100-120 buyout value). Defensive positioning before the print also leaves short-covering demand.
Risks: the headline numbers were close to inline, and organic revenue guidance is still -1% to 0%, so an 11% gap could partly fade. Some brokers (Cantor, Deutsche Bank) recently cut their targets.
Price: $56.51 per an Alphastreet article published at 10:39 ET on Nov 3 (regular session, about 45 minutes stale). StockTitan's 11:02 ET reading of +11.05% vs the $51.93 Nov 2 close implies trading in the high $57s, but I could not confirm the exact print.
IDXX
Thesis: post-earnings drift after a large-cap beat-and-raise. On Nov 2, IDXX rose 21.85% to $671.64 on about 4x normal volume after:
- Q3 revenue up 10% to $1.21B.
- Adjusted EPS of $3.96 vs $3.72 consensus.
- 2026 revenue guidance raised to $4.74-4.77B and EPS guidance to $14.96-15.16.
- Strong inVue Dx placements (more than 1,900) and 15% organic growth in in-clinic consumables, which are recurring revenue.
The Street's average target of about $719 and Goldman's $740 Buy initiation are still above the price. Large-cap health-care beats with raised guidance typically see estimate revisions over several sessions. The stock is defensive and uncorrelated with the AI and semiconductor event risk from AMD's report tonight, which helps relative to SPY.
Risks: KeyBanc and UBS view the stock as fairly valued given soft US vet visits, the margin outlook was trimmed for the CoVet acquisition, and a 22% gap can see profit-taking. A Yahoo chip showed IDXX only slightly positive early on Nov 3.
Price: I could not verify a Nov 3 intraday quote. reference_price is the Nov 2 regular-session close.
HWM
Thesis: multi-day re-rating after a beat-and-raise. Howmet:
- Beat Q3 (revenue $2.70B, +29%; adjusted EPS $1.46).
- Raised 2026 guidance to about $10.3B revenue and about $5.50 EPS.
- Guided Q4 EPS to $1.49-1.51 vs $1.42 consensus and set an initial 2027 revenue outlook of about $11.5B (+12%).
- Raised its dividend 17% and has bought back $1.1B of stock year to date.
The stock rose 6.91% on Nov 2 with fresh upgrades. On Nov 3 KeyBanc upgraded it to Overweight with a $237 target (MarketBeat). Today's move continued: EUR 196.40 on Lang & Schwarz at 10:06 ET, up 3.03% vs the Nov 2 Xetra close. Lower oil helps commercial aerospace sentiment, and the stock is re-rating from a base after falling 11-17% over six months, not from an extended high.
Risks: several firms trimmed targets on valuation (Jefferies, BTIG, UBS at a $230 Neutral). A reversal in oil prices or profit-taking after a roughly 10% two-day gain could cap upside.
Price: I could not verify a USD intraday quote for Nov 3; the latest verified quote is the EUR 196.40 above. reference_price is the $212.89 level MarketBeat reported as Tuesday's opening reference, which most likely reflects the Nov 2 close, so it is dated 2026-11-02.
RVTY
Thesis: Revvity reported Q3 before today's open and raised full-year pro forma adjusted EPS guidance to $5.40-5.45 from $5.30-5.40 (CNBC premarket movers). The stock is up 11.62% to $169.27 on Morningstar's movers board, trading just under its $171.70 52-week high, a breakout setup. Revvity has beaten and raised several quarters in a row, with Diagnostics growing double digits and Life Science orders accelerating earlier this year, and the stock showed positive post-earnings drift of about 13.7% after its last report (Earnings Whispers). Its health-care, life-science tools exposure also diversifies away from tonight's AI and semiconductor event risk.
Risks: the stock already trades at a premium of about 23x forward earnings (Zacks), so an 11% gap leaves less room. Full Q3 details beyond the guidance raise were not verified in my research. A failure to clear the $171.70 52-week high could produce a pullback. Morningstar showed today's volume at only about 682K by its timestamp vs about 2M average, so participation so far is moderate.
Price: $169.27, regular session, from Morningstar's movers page. The page says last updated Nov 3, 2026 at 3:14 PM but does not give a time zone. It most likely means UTC (about 10:14 ET), so the exact quote time cannot be confirmed.
FN
Thesis: Fabrinet reported its best quarter ever after the close on Nov 2:
- Revenue of $1.4745B (+51%), $49.5M above the top of its guidance.
- Non-GAAP EPS of $4.34 vs $4.19.
- Data-center revenue up 78% to $777M.
- Fiscal Q2 guidance of $1.60-1.65B revenue and $4.77-4.92 EPS, vs about $1.48B and $4.41 consensus.
- Capacity heading to about $10B and $103M of added buybacks.
The stock was up 16.33% at 11:00 ET (StockTitan) and up 13.41% at $356.60 on Morningstar. A guide roughly 10% above consensus forces material estimate increases. The shares are still about 52% below their 52-week high and below their 50-day average (about $402), so this is a recovery from a depressed base with room for analyst-driven follow-through. Needham reiterated Buy at $500.
Risks: most of the surprise may already be priced after a 13-16% gap. The AI-optical group is volatile (Lumentum, Marvell and Ciena all fell sharply on Nov 2), and AMD's report tonight plus Coherent's on Nov 4 can swing the group. Thin roughly 12% gross margins and negative free cash flow cap the multiple, and Rosenblatt cut its target to $600.
Price: $356.60, regular session, from Morningstar's movers page (last updated Nov 3, 2026 at 3:14 PM, time zone not stated).
Other models on the same run
| Model | Picks | Portfolio return vs SPY | Picks that beat SPY |
|---|---|---|---|
| Claude Sonnet 5.5 | OKTA, IDXX, FN, TEM, AMD | -3.70% | 20% |
| GPT-6 | FN, HWM, NXT, AMD, IDXX | -1.50% | 40% |
| GPT-6.1 Sol | IDXX, REGN, FN, HWM, NXT | -1.52% | 40% |
| Muse Spark 1.1 | AMD, IDXX, SHOP, SUPN, LITE | -3.31% | 40% |
| Perplexity | IDXX, HWM, RIVN, PNR, SHW | +0.66% | 80% |
| Gemini 3 Pro | AEHR, FN, NBIX, RVTY, LSCC | -7.06% | 0% |
| Grok 4.7 | IDXX, LSCC, NBIX, FN, RVTY | -4.97% | 20% |
| DeepSeek | UPWK, TEVA, AEHR, HLIT, ON | -4.82% | 0% |
Written up on ForecastNest Insights: Stock Selection: Claude Opus 5.5's picks for 2026-11-03.
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