{
  "title": "Microcap Engine historical microcap universe — public aggregated audit",
  "version": "1.0",
  "published": "2026-10-13",
  "audit_as_of": "2026-10-04T23:59:59Z",
  "research_window": {
    "from": "2011-10-04",
    "to": "2026-10-04"
  },
  "market_cap_ceiling_usd": 500000000,
  "exchanges": [
    "NASDAQ",
    "NYSE",
    "NYSE American (AMEX)"
  ],
  "source_types": [
    "Financial Modeling Prep active and delisted reference inventories and historical capitalization",
    "SEC EDGAR submissions and Inline XBRL registered-security cover evidence"
  ],
  "audit_runs": [
    {
      "stage": "discovery",
      "version": "fmp-microcap-universe-discovery-v1",
      "scope": "initial listing episodes",
      "metrics": {
        "active_screener_source_rows": 6079,
        "delisted_source_rows_since_start": 15683,
        "candidate_listing_episodes": 10131,
        "active_episodes": 5706,
        "delisted_episodes": 4425,
        "unique_symbol_strings": 10119
      },
      "note": "Discovery records are not independently verified permanent securities."
    },
    {
      "stage": "historical_market_cap",
      "version": "fmp-microcap-market-cap-classification-v1",
      "scope": "10,131 discovery episodes",
      "metrics": {
        "ever_observed_below_500m": 7257,
        "no_observed_below_500m": 2645,
        "no_valid_cap_history": 229,
        "conservative_pool": 7486
      },
      "note": "Ever-observed screening, not full daily point-in-time membership. An unobserved crossing is not ruled out."
    },
    {
      "stage": "identity_sanitization",
      "version": "pit-universe-identity-sanitized-v1",
      "scope": "7,486 conservative records",
      "metrics": {
        "records": 7486,
        "identity_integrity_issues": 0,
        "production_eligible_before_sec_verification": 0
      },
      "note": "Provider-supplied identity values are hints until authoritative corroboration."
    },
    {
      "stage": "sec_issuer_verification",
      "version": "pit-universe-sec-identity-v3",
      "scope": "selected active subset from conservative pool",
      "metrics": {
        "active_records_attempted": 3839,
        "issuer_verified": 3825,
        "initial_current_ticker_missing": 14,
        "cover_candidates_examined": 4337
      },
      "note": "Issuer-level evidence does not itself identify a listed security."
    },
    {
      "stage": "sec_security_verification",
      "version": "pit-universe-sec-identity-v3",
      "scope": "3,839 active attempted, 3,760 after out-of-scope exclusions",
      "metrics": {
        "security_verified": 3656,
        "in_scope_unresolved": 104,
        "out_of_scope_non_common": 79,
        "active_in_scope": 3760,
        "integrity_issues": 0
      },
      "rates": {
        "issuer_resolution_among_attempted_pct": 99.64,
        "security_resolution_in_scope_pct": 97.23
      },
      "status": "INCOMPLETE",
      "note": "97.23% measures resolution coverage, not independent identification accuracy."
    },
    {
      "stage": "successful_cover_form",
      "version": "pit-universe-sec-identity-v3",
      "scope": "3,656 verified securities",
      "metrics": {
        "10Q_family": 2710,
        "20F_family": 688,
        "10K_family": 138,
        "40F_family": 77,
        "8K_family": 43
      },
      "note": "Amendments are included in the corresponding form families."
    },
    {
      "stage": "identity_issues",
      "version": "pit-universe-sec-identity-v3",
      "scope": "104 distinct unresolved active in-scope records",
      "metrics": {
        "SEC_COVER_TICKER_NOT_FOUND": 74,
        "SEC_CURRENT_TICKER_NOT_FOUND": 14,
        "SEC_COVER_SHARE_CLASS_UNSUPPORTED": 11,
        "NO_PIT_COVER_CANDIDATES": 5,
        "SEC_COVER_TICKER_AMBIGUOUS": 3
      },
      "note": "Diagnostic occurrences total 107 because categories can overlap across the 104 records."
    }
  ],
  "limitations": [
    "The 3,839-record SEC audit examined selected active candidates, not the full 7,486-record historical candidate population.",
    "The 4,425 delisted listing episodes were not all verified with historical CIK and date-effective aliases in this audit.",
    "The available market-cap data did not independently establish daily point-in-time information availability.",
    "No independently manually adjudicated mapping accuracy or strategy return uplift was measured."
  ],
  "attribution": "Microcap Engine Research. Cite the corresponding research article and retain scope notes."
}