--- title: "Concepts · ST0x developer docs" url: https://st0x.io/docs/concepts format: markdown rendering of the HTML page --- Developer docs # Concepts Token forms, wrapping and transfers. Everything you need to know before you build with ST0x tokens: the two token forms, how they relate, how tokens are created, and when a call can fail. ## tStock and wtStock Every stock on ST0x comes in two forms. **tStock** is the issued token: one tStock carries a right to one share. **wtStock** wraps tStock so that balances never change with corporate actions, which is what pools, vaults and lending markets want. | | tStock (e.g. tTSLA) | wtStock (e.g. wtTSLA) | | --- | --- | --- | | What it is | ERC-20 receipt vault, 18 decimals. | ERC-4626 vault that holds tStock, 18 decimals. | | Shares per token | 1 tStock = 1 share. | convertToAssets(1e18) / 1e18 tStock, read on each chain. It rises when a dividend is delivered to the wrapper: at a ratio of 1.004, 100 wtStock hold 100.4 tStock. | | Splits | Balances change. | Balances stay the same; the ratio changes. | | Dividends | To be paid out for holders to claim; claiming isn’t live yet. | S01 sends them to the wrapper as tStock, raising the ratio in one step. [How](/docs/corporate-actions#dividends) . | | Good for | Holding the issued token directly. | DeFi: pools, collateral, vaults. | ## Terms - **Authorised Participant (AP)**: A firm or investor onboarded by S01, with an account at an Eligible Broker, who can mint tokens against shares and redeem them for shares. - **Eligible Broker**: A broker S01 accepts for moving shares in and out when tokens are minted or redeemed. - **Receipt**: An ERC-1155 token created with every mint, carrying that issuance’s data, so supply traces back to each issuance. ## Issuer controls ST0x tokens are built on Rain’s open-source Verifiable Asset Tokenization System (VATS), a framework for tokens backed by real-world assets. It gives the issuer three controls over tStock. Each one is set and visible onchain, so you can check its state at any time. ### Certification The issuer certifies each tStock, on each chain, until a set date: its attestation that the records behind the tokens are up to date. If a certification expires without being renewed, tStock transfers stop until the issuer certifies again. Read `isCertificationExpired()`. ### Owner freeze The token’s owner can pause all tStock balance changes until a set time, except for addresses it allows. The owner is controlled by a Safe multisig, normally through a 48-hour timelock. Read `ownerFrozenUntil()`. ### Confiscation An address the issuer grants the confiscation role can move tStock from any holder. Whether anyone holds the role is visible onchain for each token and chain. While a certification has lapsed or a freeze is on, tStock can’t move, so wrapping and unwrapping stop too. wtStock transfers themselves aren’t restricted. ## How wrapping works Wrapping converts tStock into wtStock and back. Anyone can do it, and it works on every chain where both contracts are deployed and the tStock can be transferred. 1. **Wrap**: `tStock.approve(wtStock, assets)`, then `wtStock.deposit(assets, receiver)`. You receive `previewDeposit(assets)` wtStock. 2. **Unwrap**: `wtStock.redeem(shares, receiver, owner)`. You receive `previewRedeem(shares)` tStock. The ratio can change between your preview and the transaction, for example if a dividend delivery lands in between. If you need a minimum output, check the amount received after the call. ## Identify tokens by address Always identify a ST0x token by its contract address and chain, never by its name or ticker. A token with a matching name at a different address is not a ST0x token. Every token page lists the real addresses. ## Each chain is separate Each chain has its own tStock and wtStock contracts, listed on each [token page](/tokens). Supply is minted per chain, and each wrapper has its own ratio, so one wtStock on Base is not the same amount of tStock as one wtStock on Ethereum. ## Minting and redeeming Tokens are minted and redeemed by Authorised Participants. An AP delivers shares to S01 through an Eligible Broker and new tokens are minted, each with a receipt onchain; to redeem, an AP sends tokens back and receives the shares. Because supply can move both ways, the token stays tied to the share: if it trades above the share price, APs can mint new tokens and sell them; if it trades below, they can buy tokens and redeem them. Minting and redeeming take time, so small gaps can open, especially while the market is closed. Every [mint and burn](/trust#live-stats) is public as it happens. [Become an Authorised Participant](/issuance). ## Who can hold ST0x tokens aren’t for US persons or sanctioned persons, and they are offered to the public in the EEA. Make sure your product’s audience fits; see [eligibility](/legal#eligibility). This is not legal advice. Building with the contracts needs no agreement with S01; to talk about a new stock, a new chain or working together, [get in touch](/request?kind=build). --- Risk warning You are about to purchase a product that is not simple and may be difficult to understand. The Products bear the risk that Investors may lose all or part of the invested capital. Products are unsecured debt instruments of the Issuer. Investors are exposed to the credit risk of the Issuer. The Products are not capital protected and are not covered by any deposit protection or Investor compensation scheme. Source: Base Prospectus, 30 March 2026, pp. 8 and 17. Eligibility Not for US persons or sanctioned persons. Offered to the public under the Base Prospectus in Liechtenstein, Germany, Luxembourg, France, Spain and Italy and other EEA states notified under Article 25. Minting and redemption with the issuer require an Eligible Broker account and onboarding. [Full eligibility](/legal#eligibility). Source: Base Prospectus, 30 March 2026, pp. 1, 3, 24, 38 and 69.