{
 "page": "https://prediction-market-use-cases.vercel.app/kalshi/category/health/",
 "source": "Becker Kalshi dataset (github.com/Jon-Becker/prediction-market-analysis); categories from Kalshi public API GET /trade-api/v2/series fetched 2026-10-17",
 "snapshot": "2026-10-17",
 "units": {
  "contracts": "sum of markets.volume (contracts, not dollars)"
 },
 "data": {
  "markets": 632,
  "events": 496,
  "nseries": 55,
  "vol": 8224628,
  "zero": 8,
  "settled": 578,
  "yes": 285,
  "no": 293,
  "first": "2021-07-07",
  "last": "2025-08-04",
  "by_year": [
   {
    "year": 2021,
    "markets": 210,
    "contracts": 3613737,
    "never_traded": 1,
    "settled": 210,
    "yes": 125
   },
   {
    "year": 2022,
    "markets": 330,
    "contracts": 3033220,
    "never_traded": 3,
    "settled": 330,
    "yes": 147
   },
   {
    "year": 2023,
    "markets": 17,
    "contracts": 119898,
    "never_traded": 0,
    "settled": 17,
    "yes": 5
   },
   {
    "year": 2024,
    "markets": 35,
    "contracts": 1266756,
    "never_traded": 0,
    "settled": 19,
    "yes": 8
   },
   {
    "year": 2025,
    "markets": 40,
    "contracts": 191017,
    "never_traded": 4,
    "settled": 2,
    "yes": 0
   }
  ],
  "top_series": [
   {
    "series": "CASEM",
    "title": "COVID daily case max",
    "markets": 13,
    "contracts": 1030488,
    "never_traded": 0
   },
   {
    "series": "CASED",
    "title": "COVID daily cases",
    "markets": 262,
    "contracts": 993985,
    "never_traded": 1
   },
   {
    "series": "VAROMIC",
    "title": "Omicron share",
    "markets": 16,
    "contracts": 754158,
    "never_traded": 0
   },
   {
    "series": "CASE7D",
    "title": "New COVID-19 case average",
    "markets": 25,
    "contracts": 731886,
    "never_traded": 0
   },
   {
    "series": "VAXX",
    "title": "COVID vaccinations",
    "markets": 65,
    "contracts": 655896,
    "never_traded": 2
   },
   {
    "series": "CASESURGE",
    "title": "New COVID-19 wave",
    "markets": 2,
    "contracts": 590180,
    "never_traded": 0
   },
   {
    "series": "H5N1CASES",
    "title": "H5N1 cases",
    "markets": 5,
    "contracts": 439780,
    "never_traded": 0
   },
   {
    "series": "CASE7DA",
    "title": "Return to March 2020 COVID level",
    "markets": 1,
    "contracts": 405434,
    "never_traded": 0
   },
   {
    "series": "CASEW",
    "title": "New COVID-19 cases this week",
    "markets": 55,
    "contracts": 369496,
    "never_traded": 0
   },
   {
    "series": "KXCOVVC",
    "title": "COVID new variant of concern reported",
    "markets": 1,
    "contracts": 247190,
    "never_traded": 0
   }
  ]
 }
}