Mantle Index Four Fund Review 2026: A Tokenized Crypto Index Fund

Mantle Index Four Fund, known as MI4, is a tokenized fund that gives investors a single position in a basket of large crypto assets. Press coverage from April 2025 describes it as a joint launch by Mantle and Securitize, a company focused on issuing and administering tokenized real-world assets. One headline from that period described it as a $400 million product.

The fund follows index-fund rules. It holds BTC, ETH and SOL along with other top Layer 1 and Layer 2 tokens, weights them by market capitalization within set limits, and keeps a fixed share in US dollars. The basket is rebalanced quarterly. The fund also uses staked instruments, named as mETH, bbSOL and sUSDe, to seek extra yield.

The product is described as structured for institutional investors, with traditional fund administration and a 1% management fee. One third-party write-up says shares are recorded on-chain with programmable compliance, fast settlement and real-time net asset value tracking. The public material does not name the chain, the custodian or the administrator, and it lists no audits.

An index fund holds a basket of assets in set proportions and adjusts those proportions on a schedule. MI4 applies that idea to crypto. It tracks a basket of large Layer 1 and Layer 2 tokens, with BTC, ETH and SOL named publicly, and weights each asset by its market capitalization within limits. A fixed share of the fund stays in US dollars, so the basket is not fully exposed to crypto prices at all times.

The weights are reset quarterly. If one asset grows faster than the others, its share rises until the next rebalance, when the fund sells some of it and buys the rest to restore the target mix. Investors hold a share of the whole basket rather than choosing and managing individual tokens or wallets.

Part of the fund is placed in staked instruments, including mETH, bbSOL and sUSDe. Staking earns rewards from the networks or protocols behind those assets, and the fund aims to add that income to price moves. The reward rate can change, and the staked tokens carry their own smart-contract and counterparty risks.

The fund states a 1% management fee. The public material does not list subscription, redemption, performance or administration fees, so the total cost of holding the fund is not fully visible from the public record.

Fee terms would normally appear in the offering documents given to eligible investors. Readers should ask the issuer for the complete schedule before comparing the fund with a self-custody index approach.

The public record lists zero audits for MI4. Readers should not assume the smart contracts or the on-chain share records have been independently reviewed unless the issuer provides audit reports.

Custody is not described publicly. A fund of this type usually depends on a custodian, an administrator and the issuer's legal structure, and investors need to know which parties hold assets and records. Press coverage describes the fund as a BVI partnership and Securitize as a licensed infrastructure firm, but the material does not give licence numbers or the regulator overseeing the fund. No security incidents involving MI4 appear.

The main risks are market risk, since the basket can lose value quickly, and counterparty risk from the staked instruments and the issuer. Investing in crypto-linked funds can result in losing part or all of the money put in.

This fund is aimed at institutional investors, advisers and eligible professional clients who want diversified crypto exposure in a regulated-style wrapper. Retail readers who cannot meet the eligibility rules, or who want direct control over their own tokens, will find that a self-custody approach better fits their needs.