Where IV percentile sits furthest above IV rank, latest session

WITH per_session AS (
    SELECT underlying_symbol AS u,
           date AS d,
           quantileExact(0.5)(implied_volatility) AS iv,
           sum(volume) AS vol
    FROM global_markets.options_greeks
    WHERE date >= (SELECT max(date) FROM global_markets.options_greeks) - 380
      AND iv_converged AND implied_volatility BETWEEN 0.02 AND 5
      AND abs(strike_price / underlying_close - 1) <= 0.05
      AND expiration_date BETWEEN date + 20 AND date + 60
      AND underlying_symbol NOT IN ('SPCX','KORU','SOXL','SOXS','TQQQ','SQQQ','NVDL','NVDS','NVD','TSLL','TSLQ','TSLZ','SPXL','SPXS','UPRO','SPXU','LABU','LABD','FAS','FAZ','TNA','TZA','YINN','YANG','UDOW','SDOW','BOIL','KOLD','UCO','SCO','USD','SSO','SDS','QLD','QID','ERX','ERY','DRN','DRV','CURE','SOXY','MUU','SNXX','UVXY','SVXY','UVIX','SVIX','BULZ','WEBL','WEBS','DPST','DRIP','GUSH','AGQ','ZSL','BITX','ETHU','MSTX','MSTU','CONL','DUST','JNUG','JDST','NUGT','AMDL','NUAI','VXX','VIXY')
    GROUP BY u, d
    HAVING count() >= 10
),
ranked AS (
    SELECT u, d, iv, vol,
           row_number() OVER w AS rn,
           first_value(iv) OVER w AS iv_latest,
           first_value(d) OVER w AS d_latest
    FROM per_session
    WINDOW w AS (PARTITION BY u ORDER BY d DESC)
),
agg AS (
    SELECT u,
           any(iv_latest) AS iv_cur,
           any(d_latest) AS last_d,
           count() AS sessions,
           min(iv) AS iv_lo,
           max(iv) AS iv_hi,
           countIf(iv < iv_latest) AS below_now,
           sumIf(vol, rn <= 20) AS vol_20d
    FROM ranked
    WHERE rn <= 252
    GROUP BY u
),
board AS (
    SELECT u,
           round(100 * iv_cur, 1) AS iv_now_pct,
           round(100 * (iv_cur - iv_lo) / (iv_hi - iv_lo), 1) AS iv_rank,
           round(100 * below_now / sessions, 1) AS iv_percentile,
           round(100 * iv_hi, 1) AS iv_52w_high_pct
    FROM agg
    WHERE sessions >= 200
      AND vol_20d >= 20000
      AND iv_hi > iv_lo
      AND last_d = (SELECT max(date) FROM global_markets.options_greeks)
)
SELECT u AS ticker,
       iv_now_pct,
       iv_rank,
       iv_percentile,
       round(iv_percentile - iv_rank, 1) AS percentile_minus_rank,
       iv_52w_high_pct
FROM board
ORDER BY percentile_minus_rank DESC, iv_now_pct DESC, ticker
LIMIT 12