Extreme Movers: Claude Sonnet 5.5's picks for 2026-10-29
Claude Sonnet 5.5 picked FFIV, VRT, EAT, LSTR, ENPH for a 1-day horizon. Average directional return: -0.08%. Directions called correctly: 40%.
| Experiment | Extreme Movers |
|---|---|
| Model | Claude Sonnet 5.5 |
| Prompt version | extreme-movers-v11 |
| Asked | |
| Horizon | 1-day |
| Measured from | 2026-10-29 |
| Measured to | 2026-10-30 |
| Benchmark | SPY |
| Status | Settled |
| Average directional return | -0.08% |
| Directions called correctly | 40% |
| Benchmark return | -1.03% |
The picks
| Rank | Symbol | Direction | Price change | Return in the called direction | Confidence | vs benchmark | Called right |
|---|---|---|---|---|---|---|---|
| 1 | FFIV | down | -3.29% | +3.29% | 60% | +4.32% | Yes |
| 2 | VRT | up | -1.85% | -1.85% | 55% | -0.82% | No |
| 3 | EAT | up | -2.73% | -2.73% | 52% | -1.71% | No |
| 4 | LSTR | down | +0.04% | -0.04% | 45% | +0.99% | No |
| 5 | ENPH | up | +0.91% | +0.91% | 38% | +1.94% | Yes |
The model's market view
Index moves were small on Oct 28 (S&P 500 +0.28%) after the Fed held rates at 3.75% to 4%, so the action was in single stocks. Alphabet, ServiceNow and Fortinet fell 10% to 25% after hours, and software and cybersecurity names were weak in Oct 29 premarket. AI-infrastructure and restaurant earnings were strong. I picked names with substantive earnings or guidance catalysts and leaned on post-earnings drift, with one low-confidence rebound pick on a crowded, heavily shorted stock. I could not retrieve live Oct 29 quotes for these names, so every reference price is the Oct 28 session quote from the cited page. Average dollar volume was screened using average share volume times price, which comfortably clears $20M for all five, but I could not confirm a 20-day dollar-volume figure, so that field is omitted for every pick.
Why each pick
FFIV
F5 fell about 19.4% on Oct 28 (Stockanalysis listing -19.44%; Morningstar -19.50%) after FY2027 non-GAAP EPS guidance of $18 to $18.30 only slightly exceeded the $18.03 consensus, and Piper Sandler downgraded it to neutral. The catalyst is substantive: a guidance and downgrade reset after a big run-up. A post-earnings drift continuation down is plausible, and software and cybersecurity peers (Fortinet, ServiceNow) were sharply lower in Oct 29 premarket. Risk: an oversold bounce, since the stock is already down about 19% in one session. Price $370.07 and market cap $20.96B come from the Stockanalysis losers table for Oct 28; Morningstar showed $370.63. Average volume is about 607K shares (Morningstar), so average dollar volume is roughly $200M or more by my estimate; the 20-day dollar figure is not confirmed. I could not get a live Oct 29 quote, so this is the Oct 28 session quote.
VRT
Vertiv rose about 16.5% on Oct 28 (Yahoo Finance closing report +16.48%). It reported Q3 net sales +61%, organic orders growth above 100% and raised full-year guidance across all key metrics, a substantive catalyst. AI-infrastructure demand was reinforced by Oracle's investor day, SK hynix's record AI-memory earnings and Alphabet keeping 2026 capex at $195B to $205B with significantly higher capex in 2027. Continuation up is the thesis. Risks: Alphabet's drop is weighing on tech premarket, neocloud names are down, and a +16% gap can fade. The price of $241.29 is the Morningstar quote (+15.61% on that page), which differs slightly from Yahoo's +16.48%; I used Yahoo's figure for the move, and the sign is the same either way. Market cap is computed as 384.1M shares times $241.29, about $92.7B, not read from a quote page. I could not get a live Oct 29 quote, so this is the Oct 28 session quote.
EAT
Brinker rose about 14.6% on Oct 28 (Morningstar $224.93, +$28.61) after raising fiscal-year adjusted EPS guidance to $13.30 to $13.90 versus a $13.28 consensus and lifting revenue projections. That is a substantive catalyst, and analysts had been positive (Raymond James and Jefferies upgrades earlier in October). Chipotle's after-hours beat (+5%) supports restaurant-sector sentiment, so I expect continuation up. Risks: a 15% gap after a prior run-up could be partly given back, and the broader market is soft premarket. Market cap is computed as 41.77M shares times $224.93, about $9.40B. Average volume is about 1M shares (Morningstar), so dollar volume is well above $20M by my estimate; the 20-day dollar figure is not confirmed. I could not get a live Oct 29 quote, so this is the Oct 28 session quote.
LSTR
Landstar fell about 17.2% on Oct 28 (Morningstar $139.85, -$28.96). It reported Q3 results after the close on Oct 27: revenue rose 25% to $1.512B, but EPS of $1.42 was hit by $55.3M of elevated insurance and claims costs. C.H. Robinson also fell about 12% that day, which suggests broader pressure on freight intermediaries. The catalyst is substantive (margin and cost structure), so I expect post-earnings drift lower. Risks: buybacks and a sharp one-day oversold bounce. I could not confirm what drove the C.H. Robinson move, so the sector read-through is unverified. Market cap is computed as 33.93M shares times $139.85, about $4.75B. Average volume is about 399K shares (Morningstar), so dollar volume is roughly $56M by my estimate, above the floor but not exactly confirmed. I could not get a live Oct 29 quote, so this is the Oct 28 session quote.
ENPH
Enphase fell about 16.9% on Oct 28 (Morningstar $24.61, -$5.02) to a new 52-week low after quarterly revenue dropped to $293.3M from $410.4M a year earlier and residential solar remained under pressure. The catalyst is substantive, which favors continuation, but I am taking a low-confidence reversal up: volume was about 4x average (20M vs 5M), the stock is near its low, and short interest is large (about 30M shares per Twelve Data, an older snapshot). That sets up a bounce risk, offset by rate-hike fears (about 85% odds of a December hike per Yahoo via StockTitan) that hurt solar. Market cap is computed as 130.85M shares times $24.61, about $3.22B; I did not find a current quoted market cap. Average volume is about 5M shares (Morningstar), so dollar volume is roughly $120M by my estimate; the 20-day dollar figure is not confirmed. I could not get a live Oct 29 quote, so this is the Oct 28 session quote.
Other models on the same run
| Model | Picks | Average directional return | Directions called correctly |
|---|---|---|---|
| Perplexity | VRT, ORCL, FLEX, FFIV, LPLA | -0.86% | 20% |
| Grok 4.7 | VRT, AXGN, ORCL, FFIV, ENPH | -2.44% | 0% |
| Gemini 3.6 Flash High | NVDA, TSLA, AMD, AMZN, PLTR | -2.13% | 40% |
| Muse Spark 1.1 | VRT, FFIV, ORCL, CSGP, CHRW | +1.27% | 60% |
| DeepSeek | FFIV, CHRW, ORCL, FLEX, VRT | +1.16% | 60% |
| GPT-6 | FFIV, FLEX, LH, VRT, CSGP | +1.51% | 60% |
Written up on ForecastNest Insights: Extreme Movers: Claude Sonnet 5.5's picks for 2026-10-29.
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