{
  "slug": "serp-volatility-index",
  "name": "SERP volatility index",
  "aliases": [
    "Volatility index",
    "SERP turbulence",
    "Search results churn"
  ],
  "definition": "A market-level reading of how much the results pages themselves moved across a tracked demand set, the number you check to find out whether a drop was yours or everyone's.",
  "category": "SERP volatility",
  "type": "score",
  "unit": "not established",
  "direction": "neutral",
  "verification": "review",
  "aggregation": "A daily market-level reading, averaged across the rows in the period. It is not a per-keyword measure and does not aggregate up from one; averaging days to describe a week flattens exactly the spike the index exists to show.",
  "grain": "One day and one country, for the demand set the index is built over.",
  "dimensions": [
    "date",
    "country",
    "derivation method"
  ],
  "requiredFilters": [
    "date range"
  ],
  "sources": [
    "rank-tracking"
  ],
  "reports": [
    "serp-volatility-report"
  ],
  "skills": [
    "update-week-check",
    "anomaly-investigator",
    "significance-referee"
  ],
  "verbs": [],
  "rungs": [
    "R2"
  ],
  "levers": [
    "L2"
  ],
  "questions": [
    "Was that drop us or was it everyone?",
    "How volatile were results this week?",
    "Did something market-wide happen on that date?"
  ],
  "caveats": [
    "Any such index is built over a tracked keyword set, so it describes that market and not the web, an index built on one cohort is not a general web-volatility reading.",
    "A confirmed algorithm-update announcement and a movement in the data are separate facts; a spike in the same window is correlation, and rollouts run for weeks.",
    "There is more than one score. The dataset carries a volatility score, a proxy score and a structure-movement score side by side, plus a dimension naming the derivation method, so \"the index\" is several readings that must not be compared as one series.",
    "It is keyed by date and country only. There is no platform, content-format or device axis on it, so a cut by those is not something this dataset can answer."
  ],
  "freshness": "~1 day behind, daily observation, available the following day.",
  "failureModes": [
    "Quoting a volatility number as though it were an industry-wide index rather than a reading over one tracked set.",
    "Attributing a movement to a named update because the two share a week.",
    "Comparing readings produced by different derivation methods as one series."
  ],
  "notSameAs": [
    {
      "slug": "ranking-movement",
      "why": "Opposite subjects. Ranking movement is your own keywords sorted into gainers and losers, it describes you. A volatility index describes the results pages across a tracked market, including every domain on them. Reading a quiet volatility index as 'we did not move', or a loud one as 'we were hit', inverts what each measures; the pair is only informative read together, which is the whole reason the update question exists."
    }
  ],
  "related": [
    "domain-movers-count",
    "page-one-footprint-retention",
    "search-market-share",
    "overall-average-rank"
  ],
  "workflows": [],
  "lastVerified": "2026-08-04"
}