Largest month-over-month declines in SPY month-end closes

WITH daily AS
(
    SELECT
        toDate(toTimeZone(window_start, 'America/New_York')) AS d,
        argMax(close, window_start)                          AS px
    FROM global_markets.delayed_stocks_minute_aggs
    WHERE ticker = 'SPY'
      AND window_start >= toDateTime('2006-01-01 00:00:00')
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) >= 570
      AND (toHour(toTimeZone(window_start, 'America/New_York')) * 60
           + toMinute(toTimeZone(window_start, 'America/New_York'))) < 960
    GROUP BY d
),
month_close AS
(
    SELECT
        toStartOfMonth(d)        AS m,
        toFloat64(argMax(px, d)) AS close_px
    FROM daily
    GROUP BY m
),
chained AS
(
    SELECT
        m,
        close_px,
        lagInFrame(close_px, 1) OVER (ORDER BY m ASC
            ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS prior_close
    FROM month_close
)
SELECT
    formatDateTime(m, '%b %Y')                   AS calendar_label,
    round(100 * (close_px / prior_close - 1), 2) AS spy_change_pct
FROM chained
WHERE prior_close > 0
ORDER BY spy_change_pct ASC
LIMIT 10