History (20%)
Vault history scoring for recent instability, unresolved incidents, and confirmed lifetime loss events.
History measures whether the vault has recently behaved like a stable production system.
This vector is weighted at 20%, equal to Control and Governance. Chronic instability can dampen otherwise-good vaults even when current asset, platform, and timelock inputs look strong.
What It Measures
The history vector consumes vault-scoped event aggregates from the event log.
| Signal | Treatment |
|---|---|
| Active Critical events | Time-decayed penalty |
| Active Warning events | Time-decayed penalty with diminishing returns |
| Confirmed lifetime Critical loss | Non-decaying penalty for loss-evidenced Critical events |
| Clean recent history | Small bonus when there are no recent or lifetime Criticals |
RatingChange events are excluded so the score does not consume its own output.
Time Decay
Recent Critical and Warning events matter most.
| Age bucket | Weight |
|---|---|
| ≤ 30 days | 1.0 |
| ≤ 90 days | 0.6 |
| ≤ 180 days | 0.4 |
| ≤ 365 days | 0.2 |
Events outside the scoring window do not contribute to the time-decayed component.
Warning Diminishing Returns
Warnings are compressed with a logarithmic count. The first few Warnings are a meaningful instability signal, while very high-frequency curator operations should not count linearly forever.
This preserves rank order while preventing routine operational chatter from forcing every active curator into the same outcome.
Lifetime Critical Loss Penalty
Confirmed Critical loss events do not fully decay. A vault with a proven loss event in its history carries a permanent penalty, capped so repeated historical losses do not drive the vector below zero by themselves.
The lifetime count is evidence-gated. Operational Criticals such as pauses or ownership changes remain time-decayed signals, but they are not treated as permanent loss events unless the record includes loss evidence.
Tier Ceiling
History also applies a post-composite ceiling.
| History score | Ceiling |
|---|---|
| < 4.0 | 4.9 |
| < 7.0 | 7.5 |
| ≥ 7.0 | none |
The ceiling exists to prevent a vault with chaotic recent history from publishing above the tier its operating record supports.