Vault share

Reading depth

Each view includes the earlier layers; the complete engineer or auditor page is shown by default.

BeginnerCore purpose and mental modelPractitionerAdds mechanisms and economicsEngineer or auditorAdds state and verification

Dependency check

Advanced detail assumes prerequisite knowledge

Before using practitioner mechanisms or engineer and auditor checks, review any unfamiliar dependency. These paths come from canonical depends_on relationships; Web3 Academy does not track completed lessons.

Review 6 dependencies

• AssetRequired through Asset versus claim

  1. Vault share
  2. Claim token
  3. Asset versus claim
  4. Asset

• ClaimRequired through Asset versus claim

  1. Vault share
  2. Claim token
  3. Asset versus claim
  4. Claim

• TokenRequired through Asset versus claim

  1. Vault share
  2. Claim token
  3. Asset versus claim
  4. Token

• Asset versus claimRequired through Claim token

  1. Vault share
  2. Claim token
  3. Asset versus claim

• Claim tokenDirect prerequisite

  1. Vault share
  2. Claim token

• Net asset valueDirect prerequisite

  1. Vault share
  2. Net asset value

A vault share is a proportional claim whose asset value depends on the vault's recognized net assets, eligible share supply, fees, rounding, and redemption rules.

Category: Products and vaultsContainer outline category cue

System record

Start with the economic purpose, participants, resources, and entitlements before studying implementation detail.

Why it exists

Vault shares let many depositors enter and leave a pooled accounting system without assigning each user a separate copy of every underlying position.

Traditional-finance analogy

Unit in a pooled investment vehicle is the closest comparison recorded for this concept.

Where the analogy stops

• Shares can be permissionlessly transferable, composable, and used as collateral while their underlying assets remain deployed across smart contracts.
• Token balance, modeled share value, executable redemption, and secondary-market price can diverge because of fees, queues, losses, liquidity, and integration risk.

Main actors

• ActorDepositor or shareholder
• ActorVault
• ActorStrategy or asset manager
• ActorFee recipient
• ActorRedeemer, integrator, or secondary-market trader

Assets and claims

Assets — controlled or transformed resources

Assets are resources the mechanism moves, holds, values, or transforms.

• AssetDeposited underlying assets
• AssetVault-managed net assets
• AssetVault-share tokens

Claims — entitlements and corresponding dependencies

Claims are rights to value, repayment, redemption, control, or another party's performance; each depends on an obligation or system that must honor it.

• ClaimProportional claim on eligible vault net assets
• ClaimPending deposit or withdrawal claim when applicable

A vault share is a pooled share: a proportional claim on eligible vault net assets under stated mint, burn, fee, rounding, and redemption rules.

Why it exists

One vault can hold many positions for many depositors. Shares let the vault track proportional ownership without assigning each holder a separate copy of every underlying asset, debt, reward, and fee.

Traditional-finance analogy

A unit in a pooled investment vehicle is a useful analogy. On-chain shares may be transferable, wrapped, bridged, or used as collateral before the vault can redeem its positions. The token balance, accounting value, executable redemption, and secondary-market price therefore need not be equal.

Share accounting

For a simple proportional model:

shareValue = eligibleNetAssets / totalEligibleShares
sharesMinted = depositAssets / preDepositShareValue
withdrawalAssets = burnedShares * preWithdrawalShareValue

The model must define liabilities, fees, pending deposits, queued withdrawals, virtual shares or assets, locked profit, and rounding. When a strategy earns 100 units while 1,000 shares remain outstanding, net assets can rise from 1,000 to 1,100 and modeled share value from 1.00 to 1.10 without changing holder balances.

State-transition table

Table: State-transition table

Event	Vault net assets	Eligible shares	Holder meaning
Deposit	Increase by net contribution	Increase at pre-deposit rate	Ownership should match contributed value
Profit	Increase	Usually unchanged	Existing share value rises
Loss	Decrease	Usually unchanged	Existing share value falls
Fee paid in assets	Decrease	Unchanged	All holders bear lower value
Fee paid in shares	Unchanged	Increase	Existing holders are diluted
Withdrawal	Decrease by transferred value	Burned or removed	Remaining ownership stays proportional

Step-by-step mechanism

1. Determine pre-operation net assets and eligible share supply.
2. Apply pending profit, loss, debt, fee, and queue accounting in the prescribed order.
3. Quote the operation with explicit units, limits, slippage, and rounding.
4. Transfer assets and mint shares, or burn shares and transfer or queue assets.
5. Update totals exactly once and verify the user’s post-operation ownership.
6. Expose accounting value separately from current market price and available liquidity.

Capital flow moves deposits and withdrawals. Claim flow mints, transfers, wraps, queues, and burns shares. Return flow changes share value only when underlying positions receive value, recognize gains, or allocate explicit incentives. Risk flow reduces net assets or dilutes shares and propagates when another protocol treats the share as collateral or as if it were the underlying asset.

Return source and loss allocation

The share does not pay return by itself. Its value changes because the vault’s underlying positions receive income, incur valuation changes, pay costs and fees, or suffer loss. Holders absorb net loss unless a named reserve, insurer, manager, or subordinated class bears it first.

Engineer or auditor lens

Test the first and final depositors, zero assets or shares, donations, inflation attacks, tiny values, decimal mismatch, favorable and unfavorable rounding, fee-share dilution, locked profit, negative reports, repeated claims, queued withdrawals, partial liquidity, transfer hooks, reentrancy, wrappers, bridges, and collateral integrations. No deposit may mint valuable shares without value, and no burn may transfer more than its entitlement.

ERC-4626 defines one standard share interface and exact rounding expectations. OpenZeppelin’s ERC-4626 implementation documentation describes donation or inflation risk in empty vaults for one library implementation. A vault still needs independent strategy, accounting, control, and token-behavior review. The implementation documentation was reviewed 2026-08-10.

Common misunderstandings

• “One share always equals one underlying token.” Profit, loss, fees, dilution, and rounding change the ratio.
• “Share price equals market price.” Accounting, previewed execution, limits, queues, and secondary trading are different values.
• “Transferability guarantees redemption.” The vault can be illiquid, paused, impaired, or subject to a queue.

Continue to the vault and its standardized ERC-4626 interface.

Machine-readable model

Key equations

Canonical expressions come from the structured concept record. KaTeX renders the notation, while the plain-text expression and variable table keep its meaning and units inspectable without JavaScript. Read the narrative above for the model's domain, assumptions, and rounding rules.

1. Equation 1

   $$\mathrm{shareValue} = \frac{\mathrm{eligibleNetAssets}}{\mathrm{totalEligibleShares}}$$

   Plain-text equation: shareValue = eligibleNetAssets / totalEligibleShares

   Variables and units for equation 1

   Symbol	Meaning	Unit
   shareValue	Share Value	asset or valuation units per share
   eligibleNetAssets	Eligible Net Assets	underlying-asset or selected valuation units
   totalEligibleShares	Total Eligible Shares	share or claim units

2. Equation 2

   $$\mathrm{sharesMinted} = \frac{\mathrm{depositAssets}}{\mathrm{preDepositShareValue}}$$

   Plain-text equation: sharesMinted = depositAssets / preDepositShareValue

   Variables and units for equation 2

   Symbol	Meaning	Unit
   sharesMinted	Shares Minted	share or claim units
   depositAssets	Deposit Assets	selected underlying-asset units
   preDepositShareValue	Pre Deposit Share Value	asset or valuation units per share

Assurance contract

Security properties

These structured statements define desired behavior. Their stable IDs can bind tests, invariants, specifications, audit findings, or proof results without turning descriptive review advice into an assurance claim.

Desired · not evaluated: No test, audit, or proof result is implied until scoped evidence is linked to this property.

1. SP-01Desired · not evaluated

   Shares minted correspond to contributed net value under the stated pre-deposit accounting and rounding model

2. SP-02Desired · not evaluated

   Burning shares cannot transfer more net assets than the holder's entitlement and available redemption rules permit

3. SP-03Desired · not evaluated

   Deposits, withdrawals, profits, losses, fees, donations, and queued claims preserve aggregate ownership after explicit rounding

4. SP-04Desired · not evaluated

   Token balance, accounting share value, previewed execution, maximum execution, and market price remain separately identified

Prerequisites

Direct dependencies recorded by this concept's canonicaldepends_on relationships.

• Claim tokenPath 5

  A claim token records a transferable or account-bound entitlement to assets, income, redemption, governance, or another protocol-defined benefit.

• Net asset valuePath 36

  Net asset value is the value of a product's recognized assets minus its recognized liabilities at a stated valuation time and in a stated reporting unit.

Learn next

Concepts that directly depend on this one, ranked by the recommended learning path. Check each page for additional prerequisites.

• ERC-4626 tokenized vaultPath 69

  ERC-4626 standardizes an ERC-20 share interface for vaults that accept one underlying ERC-20 asset, while leaving strategy, valuation, controls, and safety to each implementation.

Knowledge check

Quiz

Answer in your own words, then open the model answer.

What problem does Vault share exist to address?

Model answer

Vault shares let many depositors enter and leave a pooled accounting system without assigning each user a separate copy of every underlying position.

Mark as understood