Chain Health Changelog: v1 archive

Impact notes

• The composite requires non-null quality and peg factors plus peg coverage that is complete, or partial with coverage ≥ 0.95; unavailable coverage or partial coverage below 0.95 keeps health score and band null
• Bound: peg weight is 0.20, so an unobserved share of at most 5% can move the observed-only peg factor by at most 5 points and the composite by at most 1 point
• No imputation and no neutral 50: the peg factor stays observed-only and the unobserved share remains published in pegStabilityCoverage beside the composite
• Ethereum, Tron, Base, Polygon, Monad, Sonic, Celo, Scroll, and Plume, withheld under v1.6 by small unpriced holdings (Ethereum: $5.9M of $148.7B), regain a composite; Hemi at 15.9% peg coverage stays NR
• Peg factor math, the 50% rated-supply quality gate, factor weights, and bands are unchanged

Impact notes

• Zero observed peg supply publishes a null peg factor and null health score/band
• Partial coverage publishes the observed-supply-weighted peg factor plus full-universe coverage, but no composite; no partial-coverage threshold is assumed
• Fully observed chains retain the existing formula and weights; neutralImputedSupplyUsd is zero for new payloads
• Nominal par references are not observed peg evidence; their supply remains in the coverage denominator

Impact notes

• Not-rated supply is excluded from both the numerator and the denominator of the `quality` factor; the 50% rated-supply coverage gate is now the only not-rated mechanism, and below it the whole composite stays `null`
• Removed the implicit `40` (the D-grade threshold) previously assigned to unrated coins, an imputed risk judgement Pharos had not made
• 5 of 105 published chains move: manta 71 → 88, stacks 82 → 90, megaeth 50 → 54, metis 87 → 89, cardano 71 → 72 quality; health scores move by at most 5 points and no chain changes health band
• Peg stability now calls the shared `deriveDepegSignal(...)` used by the depeg pipeline; the derivation is numerically identical (unrounded bps) and no chain's `pegStability` changed
• Non-positive or non-finite prices now score neutral `50` like a missing price instead of scoring `0` or poisoning the chain average with `NaN`

Impact notes

• Added explicit Pharos chain ID to L2BEAT project aliases and a static L2BEAT snapshot sourced from the scaling summary API
• Matched chains derive Chain Environment from L2BEAT stage plus Sequencer Failure, State Validation, Data Availability, Exit Window, and Proposer Failure risk sentiments
• Unmatched chains continue to use the existing tier mapping: tier 1 = 100, tier 2 = 60, tier 3 = 20
• Safety Score chainTier and deploymentModel gain L2BEAT audit helpers only; live Safety Score outputs are unchanged

Impact notes

• `GET /api/chains` excludes frozen, defunct, and non-active stablecoins before deriving peg rates or aggregating chain supply
• The report-card dependency now reports `degraded` when `report_card_cache.degradedInputs.inputsStale` is true, instead of marking stale-input scores as fresh
• Health scores can remain computed from the cached score map, but response freshness and headers now surface the degraded upstream report-card condition

Impact notes

• Reclassified FPI, cUSD, and CEUR out of the legacy algorithmic bucket based on their reserve backing
• Active backing filters and taxonomy pages now expose only RWA-backed and crypto-backed cohorts
• Backing diversity now normalizes across the two active backing types, so an even RWA/crypto split scores 100

Impact notes

• New Chain Environment factor (20% weight): tier 1 = 100 (Ethereum), tier 2 = 60 (default), tier 3 = 20 (PulseChain, Harmony, etc.)
• Backing diversity weight reduced from 15% to 10%
• Quality weight reduced from 35% to 30%
• Concentration weight reduced from 25% to 20%
• Peg stability weight reduced from 25% to 20%
• Chains with poor infrastructure penalized: e.g. PulseChain dropped from #1 healthiest to mid-table

Impact notes

• Introduced chain health score as a 0-100 composite across four factors
• Quality: supply-weighted average of Pharos Safety Scores (null if < 50% coverage)
• Concentration: HHI-based metric rewarding stablecoin diversity
• Peg stability: supply-weighted peg proximity across all chain stablecoins
• Backing diversity: Shannon entropy across the backing taxonomy active at the time
• Health bands: robust (80-100), healthy (60-79), mixed (40-59), fragile (20-39), concentrated (0-19)
• Added /api/chains endpoint, /chains/ leaderboard page, and /chains/[chain]/ detail pages