{
 "schema_version": 1,
 "slug": "silver-britannia-1oz",
 "name": "1 oz British Silver Britannia",
 "metal": "silver",
 "oz": 1,
 "first_snapshot": "2026-10-15T05:00:54+00:00",
 "last_snapshot": "2026-11-11T14:49:33+00:00",
 "days_with_data": 27,
 "snapshots": 516,
 "daily": [
  {
   "date": "2026-10-15",
   "snapshots": 20,
   "dealers_quoted": 7,
   "median_premium_pct": 16.75,
   "lowest_premium_pct": 11.12,
   "spread_pp": 7.65,
   "spot_avg": 56.84
  },
  {
   "date": "2026-10-16",
   "snapshots": 7,
   "dealers_quoted": 7,
   "median_premium_pct": 9.51,
   "lowest_premium_pct": 4.27,
   "spread_pp": 14.2,
   "spot_avg": 57.57
  },
  {
   "date": "2026-10-17",
   "snapshots": 2,
   "dealers_quoted": 7,
   "median_premium_pct": 11.37,
   "lowest_premium_pct": 4.38,
   "spread_pp": 14.44,
   "spot_avg": 57.12
  },
  {
   "date": "2026-10-18",
   "snapshots": 12,
   "dealers_quoted": 7,
   "median_premium_pct": 11.37,
   "lowest_premium_pct": 4.38,
   "spread_pp": 14.44,
   "spot_avg": 57.37
  },
  {
   "date": "2026-10-19",
   "snapshots": 32,
   "dealers_quoted": 7,
   "median_premium_pct": 10.96,
   "lowest_premium_pct": 4.25,
   "spread_pp": 14.41,
   "spot_avg": 57.34
  },
  {
   "date": "2026-10-20",
   "snapshots": 22,
   "dealers_quoted": 7,
   "median_premium_pct": 10.4,
   "lowest_premium_pct": 4.23,
   "spread_pp": 14.22,
   "spot_avg": 57.82
  },
  {
   "date": "2026-10-21",
   "snapshots": 7,
   "dealers_quoted": 6,
   "median_premium_pct": 8.7,
   "lowest_premium_pct": 4.3,
   "spread_pp": 14.04,
   "spot_avg": 57.96
  },
  {
   "date": "2026-10-22",
   "snapshots": 23,
   "dealers_quoted": 7,
   "median_premium_pct": 10.52,
   "lowest_premium_pct": 4.58,
   "spread_pp": 15.0,
   "spot_avg": 55.02
  },
  {
   "date": "2026-10-23",
   "snapshots": 27,
   "dealers_quoted": 7,
   "median_premium_pct": 10.47,
   "lowest_premium_pct": 4.69,
   "spread_pp": 15.25,
   "spot_avg": 54.06
  },
  {
   "date": "2026-10-24",
   "snapshots": 30,
   "dealers_quoted": 8,
   "median_premium_pct": 10.91,
   "lowest_premium_pct": 4.86,
   "spread_pp": 15.41,
   "spot_avg": 54.05
  },
  {
   "date": "2026-10-25",
   "snapshots": 31,
   "dealers_quoted": 8,
   "median_premium_pct": 11.28,
   "lowest_premium_pct": 4.86,
   "spread_pp": 15.69,
   "spot_avg": 54.06
  },
  {
   "date": "2026-10-26",
   "snapshots": 18,
   "dealers_quoted": 8,
   "median_premium_pct": 11.96,
   "lowest_premium_pct": 4.52,
   "spread_pp": 15.8,
   "spot_avg": 54.1
  },
  {
   "date": "2026-10-27",
   "snapshots": 7,
   "dealers_quoted": 8,
   "median_premium_pct": 11.4,
   "lowest_premium_pct": 4.51,
   "spread_pp": 18.74,
   "spot_avg": 54.18
  },
  {
   "date": "2026-10-28",
   "snapshots": 2,
   "dealers_quoted": 8,
   "median_premium_pct": 11.23,
   "lowest_premium_pct": 4.2,
   "spread_pp": 18.92,
   "spot_avg": 54.06
  },
  {
   "date": "2026-10-29",
   "snapshots": 18,
   "dealers_quoted": 8,
   "median_premium_pct": 11.79,
   "lowest_premium_pct": 4.56,
   "spread_pp": 19.64,
   "spot_avg": 52.22
  },
  {
   "date": "2026-10-30",
   "snapshots": 26,
   "dealers_quoted": 7,
   "median_premium_pct": 13.15,
   "lowest_premium_pct": 5.16,
   "spread_pp": 21.54,
   "spot_avg": 49.68
  },
  {
   "date": "2026-10-31",
   "snapshots": 24,
   "dealers_quoted": 7,
   "median_premium_pct": 13.23,
   "lowest_premium_pct": 5.33,
   "spread_pp": 21.74,
   "spot_avg": 49.25
  },
  {
   "date": "2026-11-01",
   "snapshots": 22,
   "dealers_quoted": 7,
   "median_premium_pct": 13.23,
   "lowest_premium_pct": 5.33,
   "spread_pp": 21.74,
   "spot_avg": 49.49
  },
  {
   "date": "2026-11-02",
   "snapshots": 7,
   "dealers_quoted": 7,
   "median_premium_pct": 12.74,
   "lowest_premium_pct": 5.05,
   "spread_pp": 20.9,
   "spot_avg": 50.87
  },
  {
   "date": "2026-11-04",
   "snapshots": 20,
   "dealers_quoted": 7,
   "median_premium_pct": 12.28,
   "lowest_premium_pct": 4.89,
   "spread_pp": 16.11,
   "spot_avg": 52.42
  },
  {
   "date": "2026-11-05",
   "snapshots": 19,
   "dealers_quoted": 7,
   "median_premium_pct": 12.43,
   "lowest_premium_pct": 4.81,
   "spread_pp": 16.3,
   "spot_avg": 52.27
  },
  {
   "date": "2026-11-06",
   "snapshots": 23,
   "dealers_quoted": 7,
   "median_premium_pct": 12.42,
   "lowest_premium_pct": 4.99,
   "spread_pp": 16.3,
   "spot_avg": 52.07
  },
  {
   "date": "2026-11-07",
   "snapshots": 19,
   "dealers_quoted": 7,
   "median_premium_pct": 12.44,
   "lowest_premium_pct": 4.99,
   "spread_pp": 16.42,
   "spot_avg": 52.07
  },
  {
   "date": "2026-11-08",
   "snapshots": 21,
   "dealers_quoted": 7,
   "median_premium_pct": 12.44,
   "lowest_premium_pct": 4.99,
   "spread_pp": 16.42,
   "spot_avg": 52.38
  },
  {
   "date": "2026-11-09",
   "snapshots": 27,
   "dealers_quoted": 7,
   "median_premium_pct": 12.54,
   "lowest_premium_pct": 4.86,
   "spread_pp": 15.89,
   "spot_avg": 53.11
  },
  {
   "date": "2026-11-10",
   "snapshots": 37,
   "dealers_quoted": 7,
   "median_premium_pct": 12.3,
   "lowest_premium_pct": 4.9,
   "spread_pp": 16.23,
   "spot_avg": 52.16
  },
  {
   "date": "2026-11-11",
   "snapshots": 13,
   "dealers_quoted": 7,
   "median_premium_pct": 12.07,
   "lowest_premium_pct": 4.75,
   "spread_pp": 15.94,
   "spot_avg": 53.03
  }
 ],
 "dealers": [
  {
   "dealer": "mintbuilder",
   "snapshots": 504,
   "coverage_pct": 97.7,
   "avg_premium_pct": 4.85,
   "avg_rank": 1.45,
   "vs_market_median_pp": -6.89,
   "times_cheapest": 280,
   "premium_volatility_pp": 0.31,
   "price_changes": 277,
   "dealer_name": "MintBuilder"
  },
  {
   "dealer": "bullionstandard",
   "snapshots": 504,
   "coverage_pct": 97.7,
   "avg_premium_pct": 5.62,
   "avg_rank": 1.6,
   "vs_market_median_pp": -6.12,
   "times_cheapest": 220,
   "premium_volatility_pp": 1.16,
   "price_changes": 329,
   "dealer_name": "Bullion Standard"
  },
  {
   "dealer": "hero",
   "snapshots": 220,
   "coverage_pct": 42.6,
   "avg_premium_pct": 7.71,
   "avg_rank": 3.02,
   "vs_market_median_pp": -3.08,
   "times_cheapest": 3,
   "premium_volatility_pp": 1.14,
   "price_changes": 24,
   "dealer_name": "Hero Bullion"
  },
  {
   "dealer": "summit",
   "snapshots": 503,
   "coverage_pct": 97.5,
   "avg_premium_pct": 11.87,
   "avg_rank": 4.2,
   "vs_market_median_pp": 0.13,
   "times_cheapest": 0,
   "premium_volatility_pp": 1.35,
   "price_changes": 323,
   "dealer_name": "Summit Metals"
  },
  {
   "dealer": "sdbullion",
   "snapshots": 510,
   "coverage_pct": 98.8,
   "avg_premium_pct": 12.17,
   "avg_rank": 4.28,
   "vs_market_median_pp": 0.29,
   "times_cheapest": 11,
   "premium_volatility_pp": 0.77,
   "price_changes": 139,
   "dealer_name": "SD Bullion"
  },
  {
   "dealer": "agate",
   "snapshots": 481,
   "coverage_pct": 93.2,
   "avg_premium_pct": 16.39,
   "avg_rank": 5.36,
   "vs_market_median_pp": 4.41,
   "times_cheapest": 1,
   "premium_volatility_pp": 7.24,
   "price_changes": 123,
   "dealer_name": "Agate Metals"
  },
  {
   "dealer": "apmex",
   "snapshots": 516,
   "coverage_pct": 100.0,
   "avg_premium_pct": 20.0,
   "avg_rank": 5.75,
   "vs_market_median_pp": 8.11,
   "times_cheapest": 1,
   "premium_volatility_pp": 0.97,
   "price_changes": 342,
   "dealer_name": "APMEX"
  },
  {
   "dealer": "atcost",
   "snapshots": 349,
   "coverage_pct": 67.6,
   "avg_premium_pct": 21.21,
   "avg_rank": 6.83,
   "vs_market_median_pp": 8.95,
   "times_cheapest": 0,
   "premium_volatility_pp": 0.74,
   "price_changes": 210,
   "dealer_name": "At Cost Metals"
  }
 ],
 "method": "Premium % = price / (spot x oz) - 1 with the spot recorded in the same snapshot. vs_market_median_pp = mean over snapshots of (dealer premium - median dealer premium in that snapshot). Daily values are the median across that day's snapshots (ET days). Rank 1 = lowest premium in a snapshot. Vs market median = a dealer's premium minus the median dealer premium in the same snapshot, averaged (negative = below the market). Volatility = population std dev of a dealer's premium % across snapshots (removes spot moves). No values are interpolated; days without snapshots are absent."
}