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Function FBTC Review 2026: Wrapped Bitcoin for DeFi

Function issues FBTC, a wrapped Bitcoin asset backed by core contributors Antalpha Prime, Mantle and Galaxy Digital. DefiLlama lists about $666 million in TVL, so it is large, but users take on custody and wrapper risk.

Bitcoin

By the DappsAtlas editorial team · Updated Nov 4, 2026

DappsAtlas score

7.2/10

Good

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Our verdict on Function FBTC

7.2/10

Function FBTC suits Bitcoin holders and institutions who want BTC exposure that can move into DeFi vaults and lending markets. Its main strengths are large TVL, named contributors and published reserve and audit resources. The main caveat is custody and wrapper risk: holders depend on the issuer and its infrastructure, fees are not published publicly, and vault APYs are only estimates. Read the audits and Proof of Assets pages first.

Score breakdown

How Function FBTC scores

Security: 7.0/10
Ease of use: 6.5/10
Fees: n/a
Features: 7.5/10

Scores run from 0 to 10 and are based only on facts we could verify. Where information was missing we mark the score n/a rather than guess.

What is Function FBTC?

Function is the issuer behind FBTC, a Bitcoin-backed token aimed at making BTC usable across DeFi and traditional finance. DefiLlama says it is powered by core contributors Antalpha Prime, Mantle and Galaxy Digital, and it has been listed since August 2024.

DefiLlama shows roughly $666 million in total value locked, which puts it among the larger Bitcoin wrapper products. The homepage targets institutions, DeFi protocols, market makers, hedge funds and individual Bitcoin holders, and claims 30+ integrations.

The pitch is to turn idle BTC into a productive asset through vaults, lending and cross-chain movement. As with any wrapped asset, the benefit depends on trusting the custody and reserve setup behind the token.

How Function FBTC works

FBTC is a Bitcoin-backed token. Users get FBTC in place of BTC so the asset can move across blockchains and into DeFi apps, where native Bitcoin cannot go directly. The site says the project offers reserve and custody transparency through a Proof of Assets page.

Once a user holds FBTC, it can be put into lending markets, staking or vault strategies. The homepage lists vaults from Cian and Sentora on Ethereum, and a Kamino Sentora vault on Solana, with estimated APYs and stablecoin assets such as USDT, USDC and PYUSD alongside FBTC.

DefiLlama files the project under Bridge and lists Bitcoin as its chain. The token is meant to be multi-chain, with Swap, Bridge and aToken Swap tools linked from the site.

Pros and cons

What we like

Large TVL of about $666 million on DefiLlama suggests meaningful adoption.
Named core contributors: Antalpha Prime, Mantle and Galaxy Digital.
Two audits are listed on DefiLlama, and the site links to an Audits page.
Proof of Assets page and Dune dashboard are provided for reserve transparency.
Claims 30+ integrations, with vaults on Ethereum and Solana.
No separate governance token is required to use it.

Watch out for

Custody details beyond the stated contributors are not public, so users carry counterparty and custodian risk that must be checked in the docs.
Vault APY figures on the homepage are estimates and shown as ranges, not guaranteed returns.
Some homepage fields (TVL, holders, min amount, vault cap) render as blank, zero or NaN, which makes the live site data hard to verify.
Wrapped BTC adds smart-contract and bridge risk on top of ordinary Bitcoin ownership.
Compliance-oriented, institutional framing may mean access limits or onboarding steps for some users; the project does not say.

Function FBTC fees

Fees for minting, redeeming, swapping or bridging FBTC are not published. Users would need to check the Acquire, Swap & Bridge and documentation pages, plus the fees of any third-party vault or lending market they use.

Vault yields are shown as estimated APY ranges, and the underlying protocols, such as Aave, Kamino and the vault managers, set their own terms and costs.

Is Function FBTC safe?

DefiLlama lists two audits, and the site links to Audits, Proof of Assets and a Risk Disclosure Statement. Audit details, custodian arrangements and any past incidents are not public, so they should be verified from the official documentation.

FBTC is a wrapped asset, so holders rely on the issuer, custodians and smart contracts working as described. Vault yields also add risk from third-party lending markets and strategy managers. Nothing here is financial advice, and users should check the legal terms and eligibility for their country.

6 steps

How to get started with Function FBTC

1
Read the Documentation, Audits and Risk Disclosure Statement on the official site before depositing.
2
Check the Proof of Assets page and the Dune dashboard to see reserve and supply data.
3
Confirm the terms of service apply to you, including any eligibility or compliance requirements.
4
Use the Acquire or Swap & Bridge page to obtain FBTC, after reviewing fees and supported chains.
5
Pick a vault or integration, such as a Cian or Sentora vault, and read its cap, lockup and APY assumptions.
6
Start with a small amount and track positions, since wrapped BTC adds counterparty and smart-contract risk.

Open Function FBTC

Who Function FBTC is for

FBTC is for Bitcoin holders, DeFi users, funds and protocols that want BTC to earn yield or serve as collateral across chains. It is less suitable for people who want to hold only native BTC with no issuer or custodian risk.

Function FBTC FAQs

What is Function FBTC?

FBTC is a Bitcoin-backed token issued by Function, designed so BTC can be used in DeFi for lending, staking and vault strategies. DefiLlama describes it as powered by core contributors Antalpha Prime, Mantle and Galaxy Digital.

How much TVL does Function FBTC have?

DefiLlama lists about $666.5 million in TVL, down 0.2% over the past seven days. This is third-party data and changes over time, and the homepage itself shows placeholder values for TVL.

Which vaults can FBTC be used in?

Public sources name vaults from Cian and Sentora on Ethereum and a Kamino Sentora PYUSD vault on Solana. Estimated APY ranges of roughly 1.5% to 7.5% are shown, with an extra 1% for qualified FBTC suppliers on Kamino. These are estimates, not guarantees.

Is FBTC safe?

DefiLlama lists two audits, and the site links to an Audits page and a Proof of Assets page. Wrapped assets still carry custodian, smart-contract and bridge risk, so read the audit reports and reserve data yourself.

How do I get FBTC?

The homepage shows Swap and Bridge tools, an aToken swap and a bridge explorer, and lists a Get FBTC or Acquire option. Exact minimums and fees are not given publicly.

Does Function have a token?

No. DefiLlama shows no native token for Function FBTC. The homepage does mention a Points program, but its terms are not described publicly.

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