What problem does it solve? Trend claims like "X is taking over" are often based on single sources, spikes, or hype. This Skill turns a trend claim into an evidence-checked statement, quantifies its rate and curvature from a time series, and projects it with explicit assumptions instead of silent extrapolation. ## Core Features & Use Cases - Trend validation: Checks fad markers (single source, spike shape, no mechanism) against at least two independent series before any projection, returning a VALIDATED, UNCERTAIN, or FAD MARKERS verdict. - Quantification and projection: Computes rate, curvature, and S-curve position, then projects via naive extrapolation, OLS linear, exponential, logistic fit, or Gordon's Trend Impact Analysis with probability-weighted events. - Deterministic companion tool: scripts/trend.py (stdlib only) performs all arithmetic — CAGR, doubling time, spike detection, curve fitting, TIA adjustment — with --demo and --selftest modes. - Use Case: Given five years of EV market-share data, validate the trend, fit naive and logistic curves, adjust the 2030 baseline for events like subsidy rollback, and ship a trend card with signposts and confidence. ## Quick Start Use the trend-analysis skill to validate whether heat-pump adoption in Europe is a real trend and project it to 2030 with an assumption sheet.