Extreme Movers: Claude Sonnet 5.5's picks for 2026-10-27
Claude Sonnet 5.5 picked NU, XP, TENB, RRC, FICO for a 1-day horizon. Average directional return: +0.18%. Directions called correctly: 60%.
| Experiment | Extreme Movers |
|---|---|
| Model | Claude Sonnet 5.5 |
| Prompt version | extreme-movers-v11 |
| Asked | |
| Horizon | 1-day |
| Measured from | 2026-10-27 |
| Measured to | 2026-10-28 |
| Benchmark | SPY |
| Status | Settled |
| Average directional return | +0.18% |
| Directions called correctly | 60% |
| Benchmark return | +0.58% |
The picks
| Rank | Symbol | Direction | Price change | Return in the called direction | Confidence | vs benchmark | Called right |
|---|---|---|---|---|---|---|---|
| 1 | NU | up | -3.87% | -3.87% | 60% | -4.44% | No |
| 2 | XP | up | -2.33% | -2.33% | 58% | -2.91% | No |
| 3 | TENB | up | +4.54% | +4.54% | 52% | +3.97% | Yes |
| 4 | RRC | up | +1.82% | +1.82% | 52% | +1.25% | Yes |
| 5 | FICO | down | -0.73% | +0.73% | 48% | +0.15% | Yes |
The model's market view
On 2026-10-26 the S&P 500 rose 0.70% and the Nasdaq Composite rose 0.82% on Anthropic IPO-filing enthusiasm for AI and chip stocks, with oil easing and a heavy earnings and Fed week ahead. The largest dislocations were event-driven. Brazilian ADRs collapsed after Lula's surprise re-election, M&A repriced Surgery Partners and Range Resources, and FICO fell on mortgage credit-score competition headlines. I am betting on a partial rebound in the most oversold Brazil-linked names, momentum in a pre-earnings software name, a deal-anchored stock that follows its acquirer, and further regulatory pressure on FICO. Expect high variance, since Brazil ADRs and FICO are headline-driven.
Why each pick
NU
Nu Holdings closed the source session at $12.59, down 16.95% from $15.16, on record volume of about 338M shares versus a roughly 76M-share average. The cause was Brazil repricing after Lula's surprise re-election, which raised concerns about taxes, regulation, rates and the currency. The catalyst is macro and political, hence speculative rather than company-specific: reported operating results were strong and Nu's Q2 2026 results showed about 118M of 139M customers in Brazil. Because it fell, a bounce is a reversal with direction up. I expect capitulation-volume mean reversion, and Yahoo showed a pre-market indication of $12.81 (+1.75%) at 7:35 AM EDT on 2026-10-27, which is the freshest quote I found (about 2.5 hours stale at the time of search). Risks: further Brazilian asset selling, cabinet-pick headlines and FX weakness. Market cap $60.8B per Yahoo. Price, market cap and previous_change_percent were checked. The 20-day average dollar volume was not confirmed, so it is omitted; the only figure I saw was a Yahoo average volume of about 76M shares, which is not a 20-day dollar figure.
XP
XP Inc fell 48.36% to $15.70 in the source session from $30.41, giving back its Brazil election-trade rally after Lula's surprise win. The catalyst is political and macro, so speculative. Valuation looks stretched to the downside, with a forward P/E of about 7.7 and analyst targets well above the price. There were also governance and board-change headlines in October and some institutional selling. After a roughly 50% one-day collapse I expect a partial rebound, so this is a reversal with direction up. The latest quote I found was a Google Finance pre-market indication of $15.85 (+0.90%) at 8:19 AM EDT on 2026-10-27, which is stale by a couple of hours. Risks: continued forced selling, and it is the most volatile pick. Market cap is $8.11B per Google Finance. Price, market cap and previous_change_percent were checked. The 20-day average dollar volume was not confirmed, so it is omitted; Google Finance showed an average volume of about 11M shares.
TENB
Tenable rose 8.12% to $48.21 on 2026-10-26, a new 52-week high, after a Baird price-target raise to $50 and heavy call buying. It reports fiscal Q3 results after the close on 2026-10-28, which is outside the measurement window. The catalyst is analyst sentiment plus AI-security product momentum and a pre-earnings run-up, so it is largely speculative. I expect continuation of the pre-earnings drift, direction up. Risks: gap-up exhaustion and sector rotation. The price is the 2026-10-26 regular-session close, so it is about one session stale; I did not find a 2026-10-27 quote. Market cap was about $4.91B at the prior close of $44.59, comfortably above the $1B floor, but I did not find a market cap at the source close, so market_cap_usd is omitted. The 20-day average dollar volume was not confirmed and is omitted.
RRC
Range Resources closed at $53.56 on 2026-10-26, up about 17.7% from $45.52, after EQT agreed to acquire it in an all-stock deal at 0.987 EQT shares per RRC share. That values Range's equity at about $12.83B, or an implied $54.91 per share, a 20.6% premium. The catalyst is substantive: a definitive merger agreement with expected closing in Q1 2027. The stock trades at a spread of about 2.5% to the implied value, so I expect it to hold the gain and track EQT, with a slight positive drift as the spread narrows. Direction is up as a continuation. Risks: EQT share-price weakness, since RRC moves with the acquirer, and gas-price moves. The price is the 2026-10-26 close, about one session stale. Market cap at the source close was not found and is omitted; the $12.83B deal equity value clears the $1B floor. The 20-day average dollar volume was not confirmed and is omitted. The previous_change_percent of 17.66 comes from a closing movers list, while some articles say 'nearly 18%'.
FICO
Fair Isaac fell 13.15% to $708.07 on 2026-10-26 on volume of about 2.46M shares versus a roughly 712K average. The triggers were its decision to hold the wholesale mortgage score price flat at $10 for its Preferred Program, a Wells Fargo downgrade, price-target cuts from JPMorgan, UBS and Mizuho, and an FHFA director post promising 'more action this week' on credit-score competition. The catalyst is regulatory and competitive, so substantively negative but with uncertain magnitude. I expect continuation lower, direction down, because of the downgrade cascade, the persistent downtrend and the promised regulatory follow-up. Yahoo showed a pre-market quote of $699.00 (-1.15%) at 5:30 AM EDT on 2026-10-27, about four or more hours stale. Risk: this stock has repeatedly whipsawed sharply upward after large drops, so a short-covering bounce is a real risk. Market cap is about $15.29B per CNN at the close. Price, market cap and previous_change_percent were checked. The 20-day average dollar volume was not confirmed and is omitted.
Other models on the same run
| Model | Picks | Average directional return | Directions called correctly |
|---|---|---|---|
| Gemini 3 Pro | CLS, LITE, FICO, COHR, BE | +3.12% | 80% |
| Perplexity | NU, MELI, DASH, FIX, BE | -0.63% | 40% |
| Grok 4.7 | RRC, SGRY, XNCR, XP, FICO | +1.66% | 80% |
| Muse Spark 1.1 | SOFI, CLS, MRNA, INOD, XYL | +8.27% | 100% |
| DeepSeek | LITE, TSLA, FICO, COHR, DASH | +1.58% | 60% |
Written up on ForecastNest Insights: Extreme Movers: Claude Sonnet 5.5's picks for 2026-10-27.
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