Aave weighs BTC.b onboarding as reserve parameters shift

Aave governance is looking at BTC.b for Ethereum mainnet — specifically for the Aave V4 Core Hub — while simultaneously working through parameter changes on Aave V3 reserves.

The primary governance proposal records LlamaRisk’s support for the onboarding and Lombard’s confirmation that per-asset custody segregation for BTC.b and LBTC is planned within the next couple of weeks. No exact date is given, so that segregation remains the standing condition between support and a live listing.

BTC.b is an ERC20 token deployed on Ethereum, Avalanche, Katana, MegaETH, Monad and Stable, backed 1:1 by Bitcoin (BBTC$76,501.00▲1.05%). Lombard’s stated reserve total is 10,919.51 BTC; the Chainlink protocol-level proof-of-reserves feed reports 10,919.27 BTC. The proposal also says BTC.b held its 1:1 peg across secondary markets over the past month. Both the reserve comparison and the peg history come from the governance filing; there is no independent audit conclusion in the supplied materials.

The governance post puts approximately 2,115 BTC.b in circulation, valued at roughly $167 million — though at Bitcoin’s stated price of $76,290 on September 17, 2026, per CoinGecko, 2,115 BTC.b implies approximately $161.4 million, making the filing’s $167 million figure an approximation. Avalanche holds 2,012 BTC.b ($159 million). The governance post says Ethereum holds 72.18 BTC.b ($5.7 million), which works out to about 3.41% of stated circulating supply. The top three holders control 98.05% of BTC.b’s Ethereum supply, with the filing noting that Ethereum’s 72.18 BTC.b circulating supply makes that concentration especially narrow in absolute terms.

The filing doesn’t name those holders, so that concentration can’t be mapped to specific counterparties here.

Ethereum-side liquidity sits in a Uniswap V4 BTC.b/cbBTC pool with $7.89 million in total value locked, according to the same post. Lombard BTC Vault supplies nearly 100% of that pool’s liquidity, and BTC.b trades exclusively on decentralized exchanges — no centralized exchange listing exists. That means the proposed Aave market’s secondary liquidity depends heavily on a single concentrated source.

The governance proposal specifies bridge controls. BTC.b runs across six networks, and the CCIP bridge applies a 50 BTC.b 24-hour token-bucket capacity on every active pathway. The Bascule check on the Ethereum BTC.b contract was enabled September 1, 2026; the corresponding check on Avalanche was enabled January 29, 2026.

The architecture itself was reviewed in February 2026 and was unchanged from the prior review except for a reduction in the Security Consortium from 15 to 14 members. Loan-to-value and liquidation-threshold parameters for BTC.b are not included in the supplied governance facts, so the borrowing terms users would actually receive remain unspecified.

Alongside the listing discussion, a separate Aave governance post from LlamaRisk recommends several Aave V3 reserve adjustments based on user behavior, on-chain liquidity and position health. For Aave V3 Core, the recommended optimalUsageRatio for UUSDT$0.9991▼0.02% would drop from 94.00% to 93.00%; current USDT utilization sits at 85.8%, a 7.2 percentage-point gap to the proposed ceiling.

For Aave V3 Horizon, the recommended JAAA supply cap would increase from 40,000,000 to 50,000,000. JAAA is currently running at 93.8% cap utilization; the proposed cap would pull that down to approximately 75.0% — adding 10,000,000 units of capacity while cutting utilization by 18.8 percentage points. The same Horizon package recommends raising GHO’s base rate from 3.00% to 3.25%. TokenLogic published that GHO parameter update on September 15, 2026, one day before LlamaRisk’s reserve recommendations.

CoinGecko also lists EETH$2,443.29▲1.74% at $2,434.97 on September 17, 2026. Those prices provide the filing’s market context; they don’t resolve the custody condition or determine whether BTC.b receives borrowing power on Aave.

What the proposal does well is document controls, bridge limits, reserve comparisons and existing liquidity. What it leaves open is a 3.41% Ethereum supply share, a 98.05% top-three holder concentration, liquidity sourced almost entirely from one vault, and an onboarding condition — Lombard’s per-asset custody segregation — described only as coming within the next couple of weeks.