SolvBTC

Rejected venues wait the longest for re-review; a rejection has to earn another look before the scheduled date.

REJECTED, DESPITE REAL STRUCTURAL IMPROVEMENTS, ON A RECENT REALIZED EXPLOIT. SolvBTC is a tiered Bitcoin reserve token, not a single-custodian wrapper: a Core Reserve of native BTC plus BTCB and cbBTC backs most of the token, while a capped, rate-limited Innovative Reserve holds already-rejected wrapped assets including WBTC and FBTC. Solv has made genuine governance progress — a FROST-based multi-party signing upgrade completed in early 2026, continuous audits from three named firms, and Chainlink Proof of Reserves — more independent verification than most entries in this bridge batch. But in March 2026 a reentrancy bug in a related vault let an attacker mint far beyond the intended supply and extract about $2.7M; Solv pledged to cover the loss but the funds were not confirmed returned. Combined with a stated multi-day to two-week redemption window, this is a realized smart-contract failure five months before this review, not a hypothetical one, and it does not clear the bar for approval even with the strongest governance in this batch.

Kill criteria: the events that revoke this verdict
• Twelve consecutive months with no smart-contract exploit following the March 2026 BitcoinReserveOffering incident, with an independent post-mortem and remediation audit published
• A proposed-size redemption is demonstrated to complete within a documented, tested maximum window under stress conditions
• Innovative Reserve composition and its caps are independently verifiable on-chain, not self-reported
• The FROST multisig signer set and threshold are fully disclosed and confirmed operative

The research file

Mechanism

SolvBTC splits backing into a Core Reserve — native BTC, BTCB, and cbBTC, stated to be over 60% of total backing — and an Innovative Reserve holding assets Solv itself describes as carrying varying custodial and smart-contract risk: WBTC, FBTC, BTC.b, and tBTC. Solv imposes minting caps and cross-chain rate limits on the Innovative Reserve bucket specifically. Minting is 1:1: locking BTC or an accepted reserve asset mints SolvBTC at parity. This means SolvBTC’s risk is partially, not fully, inherited from WBTC and FBTC, both already rejected in this registry — capped and rate-limited, but not eliminated.

Control and governance

Reserve assets sit in a multisig Safe wallet system. Solv upgraded to a FROST-based multi-party signature architecture on 2026-01-29 and named institutional FROST multisig partners on 2026-03-27 — a real, dated decentralization step. Governance splits into a Governor, which sets protocol parameters and treasury decisions, and a separately operating Vault Guardian watchdog enforcing custody integrity; ”Solv Guard” monitors reserve movements in real time with governance kept separate from operations. Reserves are continuously audited by Quantstamp, CertiK, and SlowMist, plus Chainlink Proof of Reserves for ongoing auditability — meaningfully more independent verification than most entries reviewed in this bridge batch.

Incident record

A confirmed exploit in March 2026: an attacker found a double-minting reentrancy flaw in the BitcoinReserveOffering vault, triggered it 22 times, converted the resulting inflated position into roughly $2.7M of SolvBTC, and cashed out. Fewer than 10 users were directly affected; Solv pledged to cover the loss from protocol reserves and offered a 10% bounty for return of funds, which had not been returned as of this review. This is a realized, not theoretical, smart-contract failure five months before this review’s search cutoff.

Exit

Redemption burns SolvBTC and returns native BTC, but is not instant: sources describe either a weekly batch schedule with requests processed the following Monday, or a stated seven-to-fourteen-day standard processing window depending on strategy allocation and liquidity. No redemption fee is charged, but the timing friction is meaningful against a same-block wrapper redemption, and matters more, not less, in exactly the stress scenario a client would want fast exit.

Comparison

Against holding WBTC or FBTC directly, both rejected in this registry, SolvBTC’s tiered, capped, multi-audited structure is a genuine risk reduction through diversification and real governance investment. Against native BTC, it still adds smart-contract risk — realized in March 2026 — plus multi-day-to-two-week redemption friction and partial exposure to two already-rejected wrapped assets through its Innovative Reserve bucket. Of every bridge and wrapper reviewed in this batch, SolvBTC is the strongest-governed and the closest to a future reopening, but a realized loss this recent keeps it at zero for now.

Sources

The claims above trace to these. Where a number could not be independently verified, the thesis says so.

• Bitget News — Solv Protocol: SolvBTC uses BTC and BTCB as initial reserve assets · secondary · accessed 2026-08-17
  Supports: reserve composition
• DailyCoin — Solv Protocol enhances SolvBTC with asset classification · secondary · accessed 2026-08-17
  Supports: Core versus Innovative Reserve split
• GlobeNewswire — introducing SolvBTC: pioneering a unified and transparent Bitcoin reserve · primary · accessed 2026-08-17
  Supports: launch and mechanism
• Solv Protocol Docs — Solv Guard · primary · accessed 2026-08-17
  Supports: reserve-movement monitoring
• Solv Protocol Docs — smart contract governance · primary · accessed 2026-08-17
  Supports: Governor and Vault Guardian split
• GlobeNewswire — Solv names institutional FROST multi-sig partners · primary · accessed 2026-08-17
  Supports: FROST multisig upgrade
• The Block — Solv Protocol says exploit drained $2.7 million from Bitcoin yield vault · secondary · accessed 2026-08-17
  Supports: March 2026 exploit
• Solv Protocol Docs — minting and redemption · primary · accessed 2026-08-17
  Supports: redemption timing

Inherited controls

The verdict above grades the protocol layer. Every position also inherits the asset it holds and the chain it settles on. The least safe layer sets the position’s grade, and the position table names which one that is.