What does Polymarket volume vs Active Trader Addresses show?

WITH bounds AS (
  SELECT
    CAST(date_trunc('month', current_date) - interval '13' month AS date) AS window_start,
    CAST(date_trunc('month', current_date) AS date) AS end_exclusive,
    date_add(
      'day',
      -1,
      CAST(date_trunc('month', current_date) AS date)
    ) AS data_through
),
user_map AS (
  SELECT
    polymarket_wallet,
    arbitrary(owner) AS owner
  FROM polymarket_polygon.users_address_lookup
  WHERE polymarket_wallet IS NOT NULL
    AND owner IS NOT NULL
  GROUP BY 1
),
market_activity AS (
  SELECT
    CAST(date_trunc('month', t.block_time) AS date) AS month,
    t.maker AS trader_wallet,
    CASE WHEN t.is_taker_side THEN t.amount ELSE 0 END AS market_volume_usd,
    CAST(0 AS double) AS combo_volume_usd
  FROM polymarket_polygon.market_trades t
  CROSS JOIN bounds b
  WHERE t.block_month >= b.window_start
    AND t.block_month < b.end_exclusive
    AND t.maker IS NOT NULL
    AND t.amount IS NOT NULL
    AND t.amount > 0
),
combo_activity AS (
  SELECT
    CAST(date_trunc('month', t.block_time) AS date) AS month,
    t.maker AS trader_wallet,
    CAST(0 AS double) AS market_volume_usd,
    CASE WHEN t.is_taker_side THEN t.amount ELSE 0 END AS combo_volume_usd
  FROM polymarket_polygon.combo_trades t
  CROSS JOIN bounds b
  WHERE t.block_month >= b.window_start
    AND t.block_month < b.end_exclusive
    AND t.maker IS NOT NULL
    AND t.amount IS NOT NULL
    AND t.amount > 0
),
activity AS (
  SELECT
    month,
    trader_wallet,
    market_volume_usd,
    combo_volume_usd
  FROM market_activity
  UNION ALL
  SELECT
    month,
    trader_wallet,
    market_volume_usd,
    combo_volume_usd
  FROM combo_activity
),
canonical_activity AS (
  SELECT
    a.month,
    a.trader_wallet,
    COALESCE(u.owner, a.trader_wallet) AS trader_address,
    u.owner IS NOT NULL AS wallet_mapped,
    a.market_volume_usd,
    a.combo_volume_usd
  FROM activity a
  LEFT JOIN user_map u
    ON a.trader_wallet = u.polymarket_wallet
),
monthly AS (
  SELECT
    month,
    SUM(market_volume_usd) AS market_volume_usd,
    SUM(combo_volume_usd) AS combo_volume_usd,
    SUM(market_volume_usd + combo_volume_usd) AS volume_usd,
    COUNT(DISTINCT trader_address) AS active_trader_addresses,
    COUNT(DISTINCT trader_wallet) AS raw_active_wallets,
    COUNT(DISTINCT CASE WHEN wallet_mapped THEN trader_wallet END) AS mapped_active_wallets
  FROM canonical_activity
  GROUP BY 1
),
with_changes AS (
  SELECT
    m.*,
    100.0 * m.volume_usd
      / NULLIF(first_value(m.volume_usd) OVER (ORDER BY m.month), 0)
      AS volume_index,
    100.0 * m.active_trader_addresses
      / NULLIF(first_value(m.active_trader_addresses) OVER (ORDER BY m.month), 0)
      AS active_trader_index,
    100.0 * (
      m.volume_usd
      / NULLIF(lag(m.volume_usd) OVER (ORDER BY m.month), 0)
      - 1
    ) AS volume_change_pct,
    100.0 * m.active_trader_addresses
      / NULLIF(
        lag(m.active_trader_addresses) OVER (ORDER BY m.month),
        0
      )
      - 100.0 AS active_trader_change_pct
  FROM monthly m
)
SELECT
  c.month,
  b.data_through,
  b.window_start,
  b.data_through AS window_end,
  CAST(13 AS bigint) AS month_count,
  c.market_volume_usd,
  c.combo_volume_usd,
  c.volume_usd,
  c.active_trader_addresses,
  c.raw_active_wallets,
  c.mapped_active_wallets,
  100.0 * c.mapped_active_wallets
    / NULLIF(c.raw_active_wallets, 0) AS mapping_coverage_pct,
  c.volume_index,
  c.active_trader_index,
  c.volume_change_pct,
  c.active_trader_change_pct,
  c.volume_usd
    / NULLIF(c.active_trader_addresses, 0) AS volume_per_active_address_usd,
  'polymarket_volume_active_traders_monthly.v1' AS source_contract_version,
  'dune:polymarket_polygon.market_trades+combo_trades+users_address_lookup' AS source
FROM with_changes c
CROSS JOIN bounds b
ORDER BY c.month;