Tokenized Investment Funds Go Onchain: What It Means for Smart-Contract Engineers

Summary: In 2025, tokenized money-market and credit funds crossed from pilot to production, with multi-chain share classes, onchain NAV feeds, and exchange collateralization. This post distills what engineers building or integrating these funds must implement next—permissioned token design, compliance attestations, NAV/oracle plumbing, cross-chain share-class strategy, custody/TA integrations, and gas-abstracted UX—using concrete, current examples.

Why this matters now

• Tokenized Treasuries alone are a ~$9.1B onchain market as of November 27, 2025, up sharply year-on-year; public-chain RWA value tracked by RWA.xyz stands around $36B. (app.rwa.xyz)
• BlackRock’s BUIDL, launched March 2024, expanded to seven networks and surpassed $1.7B AUM by March 25, 2025; by November 2025 it was accepted as off-exchange collateral on Binance and deployed a share class on BNB Chain. (theblock.co)
• Franklin Templeton’s FOBXX (BENJI) is the first U.S.-registered mutual fund to record share ownership on public chains; it enabled P2P share transfers (April 2024) and reported ~$795M AUM (Oct 31, 2025). (franklintempleton.com)
• Circle’s USYC (tokenized MMF) is live on Ethereum, Solana, Base, and BNB Chain, redeemable into USDC with near-instant rails, and used as Binance off-exchange collateral. (circle.com)
• WisdomTree and Hamilton Lane pushed tokenized funds into multi-chain and DeFi contexts; Securitize added cross-chain share-class mobility via Wormhole and plugged tokenized funds into Aave Horizon via Chainlink’s NAVLink. (coindesk.com)

For decision-makers, “onchain fund” is no longer a proof-of-concept; for engineers, it’s a precise systems problem across compliance, issuance, pricing, transfers, custody, and integrations.

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The new onchain fund stack (2025 edition)

Below is the reference architecture we implement repeatedly at 7Block Labs, annotated with production examples.

1. Permissioned share tokens (the security layer)
2. Identity and compliance attestations (the eligibility layer)
3. NAV, pricing and distribution (the economics layer)
4. Mint/redeem flows and asynchronous settlement (the lifecycle layer)
5. Cross-chain share classes (the distribution layer)
6. Custody/TA integrations and P2P transfers (the ops layer)
7. Collateralization/DeFi hooks (the utility layer)
8. Upgradeability, admin safety and monitoring (the safety layer)
9. Gas abstraction and UX (the adoption layer)

We dive into each with implementer-level details.

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1) Permissioned share tokens: pick the right standard and controls

• Standards to know:
  • ERC-3643 (T-REX) for permissioned tokens with identity registries, compliance modules, recovery/force-transfer, and partial freezes—widely used in regulated RWAs. (eips.ethereum.org)
  • ERC-1400 suite (1410/1594/1643/1644) when you need partitions (“tranches”), document binding, and controller operations. (github.com)
  • ERC-1404 (Simple Restricted Token) if you want a lightweight transfer-check interface and human-readable restriction codes. (github.com)

Recommendation for 2025: default to ERC‑3643 for institutional funds; fall back to ERC‑1400 where partitioned balances and document binding are critical; use ERC‑1404 only for minimal gating scenarios. (ercs.ethereum.org)

Minimal transfer guard pattern (pseudocode):

// Simplified: combine allowlist + sanctions + KYC attestation checks
function _beforeTokenTransfer(address from, address to, uint256 amt) internal view {
  require(allowlist[to], "to not allowed");
  require(!ChainalysisSanctions.isSanctioned(to), "sanctioned");
  require(_hasValidKyc(to), "kyc missing/expired");
}

• Chainalysis’ sanctions oracle is live on multiple EVMs; call

  isSanctioned(address)

  in your transfer path (and mirror via offchain pre-checks). (go.chainalysis.com)

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2) Identity and compliance: attestations that travel across chains

• Implement W3C Verifiable Credentials v2.0 (a 2025 W3C Recommendation) to carry KYC/AML and investor-category claims; anchor eligibility onchain via EAS (Ethereum Attestation Service) schemas. (w3.org)

Attestation gating example (investor wallet must hold a fresh “Qualified Purchaser” claim signed by your KYC provider):

import { IEAS } from "@ethereum-attestation-service/eas-contracts/IEAS.sol";

IEAS public eas;
bytes32 public qpSchemaId;

function _hasValidKyc(address user) internal view returns (bool) {
  // Pseudocode: query EAS for the latest attestation matching qpSchemaId & user
  // Production: index offchain & cache to minimize gas; verify expiration and issuer DID.
  return AttestationLib.hasActive(eas, qpSchemaId, user);
}

• EAS open contracts and SDK enable onchain/offchain attestations with schema registries; use them to avoid hardcoding allowlists per chain. (github.com)

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3) NAV, pricing, and distributions: constant-$1 vs rising-NAV models

You’ll encounter two distinct mechanics:

• Constant NAV share (~$1) with explicit dividend accrual/payouts (e.g., BUIDL’s daily payouts; March 2025 monthly payouts set a record). Engineers must implement precision accruals, distribution snapshots, and fee-netting. (theblock.co)
• Rising NAV token with continuous accrual (no airdrops or rebases), as used by Superstate funds; price steps encode yield, simplifying downstream integrations. (superstate.com)

NAV data plumbing:

• If your fund tolerates public oracle exposure, publish NAV via Chainlink’s NAVLink or a similar aggregator; this is now live for multiple issuers and used in Aave Horizon pilots. (prnewswire.com)
• For credit/private strategies, we see RedStone powering daily NAV updates in Securitize/Hamilton Lane SCOPE; pattern: onchain NAV registry + issuer-signed updates + circuit breakers. (finance.yahoo.com)

Pro tip: even for $1 stable-NAV funds (FOBXX/BENJI, BUIDL), publish onchain accounting state (yields, cutoffs, fees) for composability and auditability. Franklin’s platform now supports intraday, second-level yield allocation—engineers should design pro-rata accruals that remain deterministic under reorgs. (ftinstitutional.com)

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4) Mint/redeem flows: asynchronous by design (and ERC-7540 helps)

• Treat subscriptions/redemptions as requests that finalize after offchain settlement checks (T+0/T+1 or batched). Use ERC‑4626 as the external interface to normalize integrations; add ERC‑7540 (asynchronous vault extension) to handle delayed claims cleanly. (ethereum.org)

Example interface shape:

// ERC-4626-like wrapper
function requestRedeem(uint256 shares, address receiver) external returns (bytes32 requestId);
function claimRedeem(bytes32 requestId) external returns (uint256 assetsOut);

Circle’s USYC exposes near-instant redemptions up to a capacity and T+0/T+1 beyond; model your queue, caps, and fees similarly for predictable UX. (circle.com)

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5) Cross-chain distribution: separate share classes, not bridges

• BUIDL publishes native share classes across Ethereum, Arbitrum, Optimism, Avalanche, Polygon, Aptos, Solana—and recently BNB Chain for the Binance collateral program—coordinated by Securitize and Wormhole. Do not bridge a single share token; issue per-chain classes and let the transfer agent (TA) and your registry enforce 1:1 supply integrity. (prnewswire.com)
• Securitize formalized Wormhole integration to move positions between supported chains while the TA remains the source of truth. Engineers should preserve per-chain pause controls and share-class metadata in an authoritative registry. (wormhole.com)

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6) Custody and Transfer Agent (TA) ops: wallets, P2P, cap table

• Your TA is the golden record. Franklin Templeton’s TA records official ownership for BENJI and now supports P2P transfers between KYC’d holders—engineers must implement transfer hooks that call out to the TA registry and enforce eligibility on both ends. (franklintempleton.com)
• Expect multi-custodian support for institutions: Anchorage, BitGo, Copper, Fireblocks are common BUIDL custodians; design whitelisting and omnibus flows. (prnewswire.com)
• Keep an eye on bank/exchange venues: DBS is piloting sgBENJI on DBS Digital Exchange, with lending/collateral pathways; your ops contracts need flexible pledge/lock mechanics and TA-initiated force transfers for collateral enforcement. (reuters.com)

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7) Collateralization and exchange integration: the new “cash leg”

• BUIDL and USYC are now accepted as off-exchange collateral (Binance) and by prime brokers (e.g., Hidden Road), turning yield-bearing fund shares into working margin assets. You’ll need robust price oracles, LTV/HLV schedules, and liquidation paths in smart contracts. (coindesk.com)
• Ensure composability: funds are increasingly referenced in DeFi money markets (e.g., Aave Horizon with NAVLink). Encode pause/guardian roles and oracle sanity checks to contain spillover risk. (cryptonews.net)

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8) Upgradeability, admin safety, and monitoring

• Use UUPS proxies for lean, flexible upgrades (OpenZeppelin). Gate

  upgradeTo

  behind multi-sig + timelock; emit upgrade events for offchain monitors. (docs.openzeppelin.com)
• Storage-layout discipline (oz-upgrades plugins) and explicit pause/freeze/force-transfer flows (per ERC‑3643/1400) are standard for regulated funds. (github.com)

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9) Gas abstraction and UX

• EIP‑4337 smart accounts + Paymasters reduce friction for KYC’d investors (e.g., sponsor gas in USDC). This is critical for enterprise wallets and compliant P2P. (eips.ethereum.org)

Pattern:

• Investor signs a

  UserOperation

  to subscribe/redeem; Paymaster checks investor’s EAS KYC attestation and sponsors gas if valid.
• Tie Paymaster policy to your TA registry to avoid sponsoring non-eligible wallets.

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Practical code patterns

Below are trimmed, audit-friendly snippets that encapsulate the core mechanics.

A. Permissioned ERC‑20 with attestations + sanctions check

pragma solidity ^0.8.20;

interface ISanctions { function isSanctioned(address a) external view returns (bool); }
interface IAttestationReader {
  function hasValid(bytes32 schema, address subject) external view returns (bool);
}

abstract contract PermissionedToken {
  ISanctions public sanctions;
  IAttestationReader public attest;
  bytes32 public kycSchema;
  mapping(address => bool) public taAllowlist; // TA-managed

  error NotAllowed();
  error Sanctioned();
  error KycMissing();

  function _eligibility(address to) internal view {
    if (!taAllowlist[to]) revert NotAllowed();
    if (sanctions.isSanctioned(to)) revert Sanctioned();
    if (!attest.hasValid(kycSchema, to)) revert KycMissing();
  }
}

• Plug Chainalysis oracle for

  sanctions

  , and your EAS schema for

  kycSchema

  . (go.chainalysis.com)

B. ERC‑4626 interface with asynchronous “claim” (ERC‑7540-style)

interface IAsyncShares /* ERC-4626 surface */ {
  function deposit(uint256 assets, address receiver) external returns (uint256 shares);
  function requestRedeem(uint256 shares, address receiver) external returns (bytes32 reqId);
  function claimRedeem(bytes32 reqId) external returns (uint256 assetsOut);
  event RedeemRequested(bytes32 indexed reqId, address indexed owner, uint256 shares);
  event RedeemSettled(bytes32 indexed reqId, uint256 assetsOut);
}

• Back this with an offchain settlement adapter that releases assets when custodian cash settles; model after USYC’s instant-cap + T+0/T+1 behavior. (circle.com)

C. Cross-chain share-class registry

struct ShareClass { uint256 id; string chain; address token; bool active; }
mapping(bytes32 => ShareClass) public shareClasses; // key: keccak256(symbol, chainId)

function registerShareClass(string memory symbol, uint256 chainId, address token) external onlyTA {
  bytes32 key = keccak256(abi.encode(symbol, chainId));
  shareClasses[key] = ShareClass({id:uint256(key), chain:_toStr(chainId), token:token, active:true});
}

• Treat each network as a distinct class; move positions cross-chain through TA-led cancel/mint or controlled bridge with TA attestation (as Securitize does via Wormhole). (wormhole.com)

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Concrete examples you can copy

• Money-market funds:

  • BUIDL: daily dividends, multi-chain native share classes (ETH, Arbitrum, Optimism, Avalanche, Polygon, Aptos, Solana; now BNB), AUM milestones and Binance collateralization. Engineering takeaway: implement dividend accounting + share-class registry + custodial allowlists. (prnewswire.com)
  • FOBXX (BENJI): SEC-registered 1940 Act mutual fund on Stellar/Polygon; P2P transfers; intraday yield calculation on Benji platform for precise distribution. Takeaway: your TA is system-of-record; integrate P2P with compliance checks and pro-rata accruals. (franklintempleton.com)
  • USYC: ERC-20/SPL tokenized MMF with near-instant USDC redemptions, multi-chain (Ethereum, Base, Solana, BNB Chain) and exchange collateral use. Takeaway: design atomic USDC rails and capacity-limited instant liquidity. (circle.com)

• Private credit:

  • Hamilton Lane SCOPE via Securitize: now multichain with Wormhole and daily NAV via RedStone; supports on-demand redemptions up to caps. Takeaway: adopt asynchronous vault patterns and NAV oracles. (finance.yahoo.com)

• Asset-manager platforms:

  • WisdomTree Connect: 13–14 tokenized funds across EVMs and RWA-focused chains (e.g., Plume) with onchain NAV for CRDT via Chainlink. Takeaway: standardize fund data feeds for DeFi integrations. (coindesk.com)

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Emerging best practices (engineer’s checklist)

• Token design
  • Use ERC‑3643 (or ERC‑1400 where partitions/docs required). Implement force-transfer with transparent events and a recovery playbook. (eips.ethereum.org)
• Identity and compliance
  • Issue W3C VC v2.0 credentials offchain and anchor eligibility onchain via EAS; add runtime sanctions checks via Chainalysis oracle. (w3.org)
• NAV and distributions
  • Publish NAV via Chainlink NAVLink or equivalent; for stable NAV funds, still expose accrual state. For rising NAV models, avoid rebases; step price. (prnewswire.com)
• Lifecycle
  • Expose ERC‑4626 and add async requests (ERC‑7540); codify instant-liquidity caps and service-levels. (ethereum.org)
• Cross-chain
  • Avoid bridging a single token; issue per-chain share classes; use TA-controlled cancel/mint or controlled interoperability (e.g., Wormhole) with audit trails. (wormhole.com)
• Custody/TA
  • Maintain TA-managed allowlists for custodian omnibus and self-custody wallets; log all corporate actions onchain for reconciliation; enable P2P where permitted. (franklintempleton.com)
• Collateralization
  • Implement robust oracle design (NAV + sanity bounds), conservative LTVs, and liquidation hooks; test with exchange/prime broker partners. (coindesk.com)
• Upgrades and safety
  • UUPS proxies with multi-sig + timelock; monitor upgrade events and oracle updates; include pause/freeze switches. (docs.openzeppelin.com)
• UX
  • Sponsor gas via 4337 Paymasters for KYC’d investors; unify flows with USDC rails. (docs.erc4337.io)

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In-depth: implementing intraday yield that survives reorgs

Franklin Templeton’s Benji platform highlights a frontier feature: “intraday yield,” allocating income by the second as shares move. To replicate:

• Maintain a high-resolution accumulator:

  (cumulativeRate, lastUpdate)

  per share class.
• On transfer/mint/redeem, settle sender/receiver accrual up to

  block.timestamp

  ; update per-address

  entryIndex

  .
• Commit daily distribution events (including weekends), but ensure transfers remain deterministic under temporary forks by settling only on finalized blocks or adding a small finality delay.

This resembles how constant-product AMMs settle fees, but using a time-indexed yield curve rather than price moves. (ftinstitutional.com)

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Network selection notes (as of December 1, 2025)

• EVM mainnet/L2s remain the primary venue for institutional funds (BUIDL, USYC, WisdomTree, SCOPE). Solana and BNB Chain are rising for high-throughput distribution and exchange collateral programs. Engineers should budget for chain-specific share classes and custody whitelists. (theblock.co)
• Non-EVM networks still feature: Franklin Templeton uses Stellar; DBS/Franklin are piloting XRP Ledger issuance for sgBENJI in Asia. Validate your identity/compliance layer is portable. (franklintempleton.com)

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What’s next in 2026: standards hardening and regulated venues

• Expect wider use of W3C VC v2.0 across brokers/custodians, normalizing cross-chain eligibility checks. (w3.org)
• More tokenized funds to publish onchain NAV via standardized oracle interfaces (Chainlink NAVLink / RedStone), enabling guarded DeFi collateralization at scale. (prnewswire.com)
• Exchange collateral programs expand: Binance has added BUIDL/USYC; similar integrations may follow at other venues, pushing engineers to formalize oracle and liquidation standards for fund shares. (coindesk.com)

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A concise build plan you can execute

• Week 0–2: Choose token standard (ERC‑3643/1400), define share classes per target chains; stand up TA registry and sanctions oracle integration. (eips.ethereum.org)
• Week 2–4: Implement ERC‑4626 wrapper with async redeem (ERC‑7540-style), wire NAV oracle (NAVLink or RedStone); write distribution accounting (daily or continuous). (ethereum.org)
• Week 4–6: Integrate EAS-based KYC attestations (plus revocation flow); add 4337 Paymaster for gas sponsorship; deploy UUPS with timelock/multisig governance. (attest.org)
• Week 6–8: Stand up custodian allowlists, omnibus flows, and P2P constraints; test collateralization on a pilot venue (Aave Horizon-style or prime broker sandbox). (franklintempleton.com)

Ship with exhaustive event logs, circuit breakers, and playbooks for force transfers, oracle outages, and cross-chain desyncs.

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Closing thought

Tokenized funds are now real infrastructure. If you ship the right controls (permissioned tokens, attestations, NAV oracles), the benefits—24/7 settlement, composable collateral, automated treasury ops—are immediate. The winners in 2026 will be the teams who treat compliance, pricing, and cross-chain share classes as first-class software problems—because they are.

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Sources

• RWA market data and Treasuries totals. (app.rwa.xyz)
• BlackRock BUIDL growth, multi-chain footprint, dividends, and Binance collateral. (theblock.co)
• Franklin Templeton BENJI: P2P transfers, AUM, intraday yield feature. (franklintempleton.com)
• Circle USYC multi-chain, near-instant redemptions, and Binance collateral. (circle.com)
• Securitize cross-chain (Wormhole) and DeFi NAVLink integrations. (wormhole.com)
• ERC standards and 4337 Paymasters. (eips.ethereum.org)
• Hamilton Lane SCOPE multi-chain + RedStone NAV. (finance.yahoo.com)
• WisdomTree tokenized fund expansion and NAV onchain. (coindesk.com)
• Chainalysis sanctions oracle (for onchain screening). (go.chainalysis.com)

7Block Labs builds regulated-grade onchain fund infrastructure. If you want a working reference implementation of the patterns above (standards-compliant, audited, and tailored to your custodian/TA), we’re happy to help.