Earn: protocol vault
For depositors: how the protocol vault backs every trade, how to deposit USDC for NOE and withdraw again, the fees and cooldown, and the risk you underwrite.
This guide is for depositors: what the protocol vault is, how to deposit USDC and withdraw it, and the risks you take on as a liquidity provider. Everything here runs on Stellar testnet with test funds; see Getting started if you do not have test USDC yet.
Looking for vaults run by individual traders? That is a different product; see Trader vaults. This page covers the protocol's own liquidity pool, the Earn page in the app, labelled "Noether Vault".
What the protocol vault is
The vault is the counterparty to every trade on Noether. When a trader opens a position, the vault backs the other side: if the trader closes at a profit, the vault pays that profit; if the trader closes at a loss, the loss flows into the vault.
In return, the vault collects revenue:
- Trading fees, which the market sends to the vault on every open. A protocol share, set to 20% at deployment, goes first to the insurance buffer and, once the buffer is full, to a treasury; the rest accrues to depositors.
- Trader losses: when traders lose, the pool grows.
- Funding payments owed by traders, settled when their positions close.
As a depositor you own a slice of this pool, so your deposit grows when the pool grows, and shrinks when traders win.
The NOE token
When you deposit USDC, you receive NOE, the vault's share token. NOE is a regular Stellar asset (code NOE), so holding it requires a one-time NOE trustline in your wallet; the Earn page adds it for you with a single signature if you do not have one.
Share pricing is simple: the NOE price equals the vault's assets under management divided by the NOE in circulation. Trading fees and trader losses push it up, trader profits push it down. Your NOE balance is your pool share, and its value in USDC is balance times NOE price; the live price is in the "NOE Token Price" card on the Earn page.
Deposit USDC
Open Earn in the top navigation (or the "Open Noether Vault" button on the Vaults page). You need a connected wallet, test USDC and a little XLM for gas.
Add the NOE trustline (first time only)
If your wallet has no NOE trustline yet, the deposit button is replaced by a trustline warning with an add-trustline button. Approve the single wallet signature; the page confirms with "NOE trustline added — you can now deposit". You only do this once.
Enter an amount
On the Deposit tab, type a USDC amount in "You Pay" (the Max button fills 95% of your balance, leaving headroom for fees and gas). "You Receive" previews the NOE you will get, and the rows below show the current exchange rate and the deposit fee. The fee is read live from the contract; it is currently 0.30%.
Confirm in your wallet
Click "Deposit USDC" and approve one wallet signature. On success the NOE lands directly in your wallet.
Principal at risk
The deposit screen reminds you at the point of deposit: "Pool value falls when traders profit — principal at risk." Your NOE can be worth less USDC than you put in.
Withdraw USDC
Withdrawing converts NOE back to USDC at the current NOE price, minus a 0.30% withdraw fee. Because NOE is a standard Stellar asset, the vault needs your permission to take it back, so a withdrawal takes two wallet signatures, which the page announces up front: "Withdrawing takes two wallet signatures — first approve NOE, then withdraw. Up to ~40s total."
Cooldown after a deposit
The contract blocks withdrawals for 30 minutes after your latest deposit, to stop deposits timed around a trader's payout. If you hit it, the app says withdrawals unlock after a short cooldown; wait and retry.
Enter an amount
On the Withdraw tab, type a NOE amount in "You Pay" (Max selects your full NOE balance). "You Receive" previews the USDC out, with the exchange rate and fee shown below.
Signature 1: approve NOE
The button shows "1/2 Approving NOE…" while your wallet asks you to approve the vault to spend your NOE. The approval expires after roughly a month, so a stalled withdrawal does not leave an open-ended permission.
Signature 2: withdraw
The button switches to "2/2 Withdrawing…" and your wallet asks for the actual withdrawal. On success the USDC is in your wallet.
If something fails, the error tells you exactly where you stopped: a failure at step 1 means "NOE approval failed — nothing was withdrawn"; a failure at step 2 means the approval went through but no USDC left the pool. In both cases your funds are unchanged; just retry.
Withdrawals can never pull out liquidity that is reserved to pay open positions. If the vault's USDC balance after your withdrawal would fall below what is reserved for open positions, the transaction fails rather than shortchanging traders; try a smaller amount or wait for positions to close.
Fees at a glance
| Action | Fee | Notes |
|---|---|---|
| Deposit | 0.30% | Deducted from your USDC before your NOE is calculated |
| Withdraw | 0.30% | Deducted from your USDC proceeds |
Both fees are read live from the contract on the Earn page (they display as "—" if the read fails, never an assumed number), and both stay in the pool, so as an ongoing depositor you also benefit from other people's entry and exit fees.
Risks
You take the other side of trader PnL
When traders profit, the pool value decreases, and your NOE may be worth less USDC than you deposited. This is the core trade-off of being the house, not an edge case.
What limits the downside:
- An insurance buffer pays first. The vault keeps a separate buffer of first-loss capital outside the NOE price: when a winning trader is paid out, the buffer is drained before LP funds are touched. It is fed by half of every liquidation penalty and by the protocol's share of trading fees, up to a target of 10% of the payouts reserved for open positions. Its current size is on the Insurance Fund card of the Earn page.
- Open-interest caps bound exposure. Every new position reserves its full potential payout in the vault. Per market, open interest on either side is capped at 25% of vault assets and the net long-minus-short skew at 15%; across all markets, total reservations are capped at 70% of vault assets. Opens that would breach a cap are rejected, so the vault can never be fully committed to one market, one direction, or to trades in aggregate.
- Accounting follows real money. The pool is credited only for USDC that actually arrives, and a trader's loss on an isolated position can never exceed that position's own collateral.
These guardrails reduce the risk; they do not remove it. On testnet everything is play money, so this is the safest possible place to watch the mechanics in action.
Why APR shows "—"
The "Current APR" card on the Earn page shows an em dash with the note "Shown once fee revenue is tracked". A real APR needs a history of fee revenue, and the app deliberately refuses to fabricate a yield number in the meantime. The same rule applies across Noether: an unknown value renders as "—" or a stale badge, never a made-up figure.
Track your position
The "Your Position" card on the Earn page shows your NOE balance, its current USDC value and your share of the pool. Below it, a transaction history lists your past vault activity. If a balance read fails you see "Couldn't load your position" rather than misleading zeros.
Questions about anything here? Check the FAQ, or dig into the mechanics on the trading mechanics and contracts pages.
Trading
The trader's manual for the testnet app: pairs and limits, every order type, isolated and cross margin, fee tiers, funding and how liquidation pays out.
Trader vaults
Copy-trading vaults on the Vaults page: how depositors buy shares and withdraw, how leaders create, trade and get paid, and the on-chain rules for both.