Post-Earnings Delta Calculation

Use This Skill When

• The user wants to explain why a stock moved after an earnings release.
• The task requires comparing reported results or guidance against consensus, prior guide, or buy-side expectations.
• The work needs a surprise bridge, revision read-through, or a view on whether the reaction was proportional.
• The user needs a reusable post-print framework rather than a loose narrative recap.

Required Inputs

• company and, if available, ticker
• reporting period or earnings event date
• reported results: revenue, gross margin, operating income or margin, EPS, free cash flow, and segment results when relevant
• expectation baseline: sell-side consensus, company guidance midpoint, whisper number, or prior quarter implied trajectory
• guidance changes: next-quarter and full-year revenue, margin, EPS, or capex guidance
• market reaction window: after-hours, next day close, 3-day move, or another explicitly defined period
• supporting commentary: earnings call, shareholder letter, prepared remarks, or management Q&A
• If some inputs are missing, proceed with the highest-quality available baseline, explicitly label missing fields, reduce the precision of the conclusion, and do not fabricate surprise magnitudes or driver bridges.

Workflow

1. Define the event scope: company, quarter, benchmark expectation set, and exact reaction window.
2. Build a compact reported-versus-expected table for the metrics that actually moved the stock.
3. Quantify each surprise using absolute difference, percent difference, and basis-point or dollar contribution where possible.
4. Separate the read into:
   • print quality: revenue, margin, EPS, cash conversion
   • guidance delta: next quarter, full year, and implied exit rate
   • mix and quality: segment mix, pricing, volume, customer concentration, one-time items
   • narrative delta: tone, demand commentary, backlog, competitive remarks, capital allocation signals
5. Compare the reaction with what was already priced in:
   • prior stock performance into the print
   • consensus versus whisper gap
   • whether the beat was low quality or high quality
   • whether the reaction was driven by forward guide more than the reported quarter
6. If enough historical data exists, add context:
   • historical beat or miss distribution
   • reaction versus prior earnings events
   • simple z-score or percentile framing
7. Conclude with the main causal drivers of the move, what remains uncertain, and what to monitor into the next print.

Output Requirements

• Start with a one-paragraph headline read that answers: what happened, versus what baseline, and why the stock moved.
• Use explicit labels for Fact, Assumption, and Inference whenever the distinction could be ambiguous.
• Keep units visible in every quantified statement: %, bps, $, x, or std dev.
• State the comparison baseline for every surprise metric.
• Identify whether the move was driven mainly by reported results, forward guidance, mix or quality, management commentary, or expectations positioning.
• If any important metric is unavailable, add a Missing Data note instead of estimating a number.

Output Template

Quality Checks

• Confirm every surprise figure reconciles to a stated baseline.
• Check that the narrative explains both the print and the guide, not only one of them.
• Verify that one-time items are identified before calling a beat "high quality."
• Ensure the stock-move explanation ranks drivers instead of listing them as equal.
• Re-read the final output and remove any claim that lacks a source or a clearly marked inference tag.

Guardrails

• Separate reported facts from inferred drivers at all times.
• Do not mix consensus, company guidance, and whisper expectations without naming the baseline.
• Do not invent estimates for missing segment metrics, historical z-scores, or buy-side expectations.
• Do not claim causality from correlation alone; if the driver is plausible but unproven, mark it as an inference.
• Avoid false precision when the source data only supports a directional conclusion.

Example Prompts

• Calculate the post-earnings delta for NVDA and decompose the move into revenue, margin, and guidance drivers.
• Quantify the earnings surprise for this quarter using z-score and explain whether the stock reaction was proportional.
• Compare the reported results and updated guide against consensus, then explain the next-day move with a ranked driver bridge.