This rule uses pattern recognition to identify statistically unusual transaction amount patterns that often indicate fraud or money laundering.

System generates alerts for:
1. Suspiciously round amounts (1000, 5000, 10000, etc.)
2. Repeated unusual amount patterns
3. Statistical deviation from normal merchant amount distribution

Unusual amount patterns can indicate:
- Money laundering (specific amounts being moved)
- Card testing (fraudsters using standard test amounts)
- Merchant fraud (processing predetermined fake transactions)
- Structuring to avoid reporting thresholds
- Automated fraud tools (using programmatic amounts)

Pattern types monitored:
- Excessive round numbers (ending in 00 or 000)
- Repeated identical amounts across transactions
- Sequential amount patterns (100, 200, 300...)
- Just-below-threshold patterns (avoiding detection limits)

Alert-only approach enables:
- Pattern documentation without transaction disruption
- Cumulative analysis over time
- Merchant education on suspicious patterns
- Investigation when patterns confirm fraud indicators

Fraud analysts evaluate:
- Merchant business type (some legitimately have round amounts)
- Transaction context and supporting documentation
- Historical merchant patterns
- Correlation with other fraud indicators

Helpful for identifying subtle fraud schemes that individual transaction monitoring might miss.