Identify anomalous daily spending by subaccount

Postgres SQL, as run

select date_trunc('day', charge_period_start) as day,
       provider_name,
       sub_account_id,
       sum(effective_cost) as daily_effective_cost
from focus.cost_and_usage
where charge_period_start >= $1::timestamptz
  and charge_period_end < $2::timestamptz
group by 1, 2, 3
order by abs(sum(effective_cost)) desc nulls last, day, provider_name, sub_account_id
limit 500

Parameters: $1 = period_start, $2 = period_end

Original FOCUS SQL

SELECT
  DATE(ChargePeriodStart) AS Day,
  ProviderName,
  SubAccountId,
  SUM(EffectiveCost) AS DailyEffectiveCost
FROM focus_data_table
WHERE ChargePeriodStart >= ? and ChargePeriodEnd  < ?
GROUP BY
  DATE(ChargePeriodStart) AS StartDay,
  ProviderName,
  SubAccountId