Flow anomalies
Z-score-based detection of unusual flows between stablecoins.
Flow anomalies are 15-minute windows where the volume on a (from_token, to_token) edge exceeded the 7-day rolling baseline by ≥3σ.
Useful for detecting:
- Sudden arb activity between stables
- Migration events (users rotating between stables)
- Bridge inflows / outflows
- Suspicious wash patterns
GET /v1/stablecoins/flow-anomalies
Free tier.
curl "https://pelletfi.com/api/v1/stablecoins/flow-anomalies?limit=20"Response
{
"anomalies": [
{
"from_token": "0x20c000000000000000000000b9537d11c60e8b50",
"to_token": "0x20c0000000000000000000000000000000000000",
"window_start": "2026-04-13T22:15:00Z",
"window_end": "2026-04-13T22:30:00Z",
"observed_flow_usd": 1820000,
"baseline_mean_usd": 240000,
"baseline_stddev_usd": 95000,
"z_score": 16.6,
"tx_count": 47,
"detected_at": "2026-04-13T22:32:18Z"
}
]
}Sorted by window_start DESC, ABS(z_score) DESC so the most recent + most extreme anomalies appear first.
Webhook event
Each new anomaly fires flow_anomaly.detected. See Webhooks.
Detection model
For each (from_token, to_token) edge:
baseline = aggregate flows from last 7 days (excluding the latest 15min window)
observed = sum(flows) in latest 15min window
z = (observed - baseline_mean) / baseline_stddev
if abs(z) >= 3.0 → anomalyOnly edges with ≥10 historical observations get scored (avoids false positives on cold edges). Detector runs every 15 minutes.
Time-travel (?as_of=)
curl 'https://pelletfi.com/api/v1/stablecoins/flow-anomalies?as_of=24h'Returns anomalies with window_start at or before as_of. Useful for reconstructing what flow signals were visible at any past moment.