Borrow
Deposit stock tokens, choose an amount and a rate, receive fyUSD. What the two fields mean, what the numbers are, and what determines your liquidation price.
Opening a position asks you for two numbers: how much you want to borrow, and the annual rate you are willing to pay. Everything else is derived.
What you need first
- Stock tokens of an active branch in your wallet. At launch: SPY and QQQ.
- A debt of at least 100 fyUSD fyUSD. Below that the position cannot exist.
- No existing position on the same branch from the same address. One address, one position per branch.
Rules R-5.1.1, R-5.3.1
The collateral ratio you must clear
Your collateral ratio is the dollar value of your deposit divided by your debt. To open — or later to increase your risk — it must land at or above the minting ratio for the branch's tier.
| Tier 1 (SPY, QQQ, third ETF) | Tier 2 (GLD, IWM) | |
|---|---|---|
| Minimum ratio to open | 125% | 133.33% |
| Maximum loan-to-value | 80% | 75% |
| Liquidation threshold, at every hour | 115% | 120% |
| Liquidation bonus paid to the liquidator | 5% | 7% |
The gap between 125% and 115% is your working room: the price may fall 8% from a freshly opened tier 1 position before it becomes liquidatable. It is deliberately not larger: the protocol constrains its risk through lending caps indexed to how much collateral the market can actually absorb — invisible to you — rather than through a stingy loan-to-value, which is the first number everyone looks at.
Rules R-5.2.1, R-13.1, P8
The one number that matters
How it is calculated
That is the only risk figure the interface shows you. There is no health factor, no coloured gauge, no score. If the price of one token falls to that level, your position can be liquidated in part.
Worked through: you deposit 20 SPY at $500, so $10,000 of collateral, and borrow 5,000 fyUSD at 4%.
| Origination fee (7 days of interest at your rate) | 3.84 fyUSD |
| Debt recorded | 5,003.84 fyUSD |
| Collateral ratio | 199.8% |
| Liquidation price | $350.27 per SPY token |
| Fall you survive | 29.9% |
| Interest for a full year | ~200 fyUSD |
Rules R-1.1.1, R-15.1.2, R-5.6.1
The rate you choose
Your rate is anything from the tier floor to 100%. The floor is the greater of a fixed value (1.5% for Tier 1, 3.0% for Tier 2) and a multiple of a USDG reference borrow rate read on-chain and clamped to 2–6%. At a reference of 3.6%, the Tier 1 floor sits at 1.8%.
A low rate is cheap and puts you at the front of the redemption queue. A high rate is expensive and pushes you back. Neither is wrong; see Interest rate and delegation and Redemption before you pick.
Guarantee
Once set, your rate can only be changed by you, or by a delegate you authorised inside bounds you chose. No market condition, no utilisation curve and no key can move it.
Rules R-5.7.1, R-5.7.3, R-5.8.1
The origination fee
Seven days of interest at your own rate, added to your debt rather than deducted from your proceeds. At the Tier 1 floor that is 0.0288% of the amount borrowed. It counts toward your minimum debt, your caps and your resulting collateral ratio. There is no fee to close, and no fee to repay.
Rule R-5.6.1
How much the branch will lend you
Two limits apply, both computed on-chain at the moment you press the button.
Your personal cap. For the first 90 days, the smaller of $50,000 and 10% of the branch's ceiling. Afterwards, the smaller of the market depth your position could be sold into and 10% of the branch ceiling.
The branch ceiling is the smallest of four terms: a multiple of measured market depth at 2% slippage (4.0× for Tier 1), a share of the token's on-chain market capitalisation (15% for Tier 1), a dated absolute step, and a share of the sum of all active branches' steps. The dated steps for SPY and QQQ, counted from activation:
| From | Absolute ceiling | Condition |
|---|---|---|
| Day 0 | $100,000 | observation period |
| Day 14 | $1,000,000 | — |
| Day 90 | $2,000,000 | no bad debt ever recorded |
| Day 180 | $3,000,000 | no bad debt ever, and branch ratio at or above 200% at the moment you mint |
If bad debt is ever recorded on a branch, its ceiling stops permanently at the last step whose conditions held. No key can raise it.
Guarantee
A ceiling that falls below the debt already outstanding blocks new borrowing. It never triggers a liquidation.
Rule R-5.4.5
When there is not enough remaining capacity for the amount you want, the interface offers a queue: you are notified when capacity frees up. There is no priority to buy and no way to jump it.
Rules R-5.4.1, R-5.4.3, R-5.4.4, R-5.4.6
When opening is not available
Borrowing needs a fresh, valid price. It is therefore unavailable while the branch's oracle is paused for a corporate action, while the feed is stale, while a circuit condition holds, while the sequencer is down, during the 24 hours before a known corporate action takes effect, while the branch is in mint freeze, and outside the regular and extended sessions.
Depositing collateral and repaying are available in all of those states. That asymmetry is the point: you can always reduce your risk, you cannot always increase it.
Rules R-4.4.1, R-5.1.2, R-4.3.8
After you open
Your position enters a sorted list ordered by rate, which is what redemptions walk through. The interface shows you where you stand in it. Interest accrues continuously and is capitalised each time you touch the position; it is minted to the Stability Pool as it accrues, so total fyUSD supply always equals total debt by construction.
Rules R-5.5.1, R-5.5.3, R-2.1.3
Last reviewed: 2026-09-07 · Spec v0.4
What Fyber is, and what it is not
Which category of financial product this is — an immutable CDP, not a bank deposit, not e-money, not a broker, not a margin account — and what follows from that.
Manage your position
Add collateral, repay, borrow more, withdraw, close, and claim your surplus — which of these are always available, and which depend on market state.