Both funds rebased to 100 at the start of the window, month by month

WITH
    month_close AS
    (
        SELECT
            toStartOfMonth(date)           AS m,
            ticker,
            argMax(toFloat64(close), date) AS px
        FROM global_markets.stocks_daily_aggs
        WHERE ticker IN ('USO', 'USL')
          AND date >= '2021-01-01'
          AND date <  '2026-01-01'
        GROUP BY toStartOfMonth(date), ticker
    ),
    first_close AS
    (
        SELECT
            ticker,
            argMin(px, m) AS px0
        FROM month_close
        GROUP BY ticker
    )
SELECT
    toString(mc.m)                                           AS month,
    formatDateTime(mc.m, '%b %Y')                            AS as_of_label,
    round(anyIf(mc.px / fc.px0 * 100, mc.ticker = 'USO'), 2) AS uso_index,
    round(anyIf(mc.px / fc.px0 * 100, mc.ticker = 'USL'), 2) AS usl_index
FROM month_close AS mc
INNER JOIN first_close AS fc ON mc.ticker = fc.ticker
GROUP BY mc.m
ORDER BY mc.m