> ## Documentation Index
> Fetch the complete documentation index at: https://docs.finwatch.finance/llms.txt
> Use this file to discover all available pages before exploring further.

# sum()

**Signature:** `sum(<condition>, "<time_window>")`

**Parameters:** Same as `count()`.

**Return Value:** A float representing the sum of the `amount` field for matching transactions.

**Description:** Calculates the total monetary value of all matching transactions within the time window. Essential for detecting structuring (smurfing) or unusual outflow volumes.

**Example: High Outflow Detection**

```shellscript lines theme={null}
rule SourceHighOutflow {
    description "Source account has high outflow volume in 24h."

    when sum(when source == $current.source, "PT24H") > 5000

    then review
         score   0.5
         reason  "High cumulative outflow from source in 24 hours"
}
```