Your borrowing limit
Why the figure on the screen is usually below 80%, what moves it, how fast it comes back, and why none of it touches the threshold at which you are liquidated.
Spec v0.9.1, reviewed 2026-09-08
The interface shows one number when you open a position: the maximum right now, with the ceiling for your category in brackets behind it — "max now: 70.6% (ceiling for the category: 75%)". That order is deliberate: the figure you can actually borrow at comes first, and the round number of the tier is context. It is almost never that round number. Two things pull it down, they are shown separately, and neither of them can move your liquidation threshold.
Guarantee
This limit concerns new borrowing, and withdrawals that increase your risk. Taking collateral back while repaying at least as much is judged on your tier's ceiling instead. Your liquidation threshold never changes: 115% on the index and gold branches, 122% on the large caps, 140% on the four most volatile names, at every hour of every day.
Rules R-6.1.3, R-19.16.4, invariant 68
The two axes
The volatility of the stock. Once per 24 hours slot, aligned on midnight UTC, each branch records its own reference price and recomputes the realised volatility of the last 7 days and the last 30 days. The sample is the median of 3 readings, so no single moment of the day can become the figure on its own. It takes the larger of the two and asks a single question: how far could this stock fall over the next 3 days, in the worst 1% of trajectories at this volatility? Whatever is left, after a margin of 2% for execution, is what it will lend.
The limit of the day
limit = (1 − 2.33× × volatility × √(3 days ÷ 365) − 2%) ÷ liquidation threshold
then clamped between the tier floor and the tier ceiling
The quality of the price. On top of that, a haircut of tier maximum × (1 − confidence) applies to the value of your collateral. Confidence comes from how many independent sources answered and how far apart they are. On a Saturday morning with seven live sources on SPY and 0.26% of dispersion, the haircut was 79.0% away from the ceiling: the available loan-to-value was 79.0% instead of 80%.
The two multiply, and the interface names both.
What the ceiling and the floor mean
| Tier | Ceiling | Floor | What the floor means |
|---|---|---|---|
| 1 — index funds, broad-market funds, gold | 80% | 60% | Borrowing would only reach the floor at a volatility around 130% a year, which SPY and gold have never printed |
| 2 — mega caps, SLV and five large caps | 75% | 50% | Around 165% a year; Nvidia's worst seven-day reading in three years was 153% |
| 3 — TSLA, PLTR, COIN, NFLX | 65% | 40% | Around 195% a year; Coinbase touched it 0.7% of the time |
Borrowing never closes because of volatility. Below the floor the limit stops falling, and a withdrawal that reduces your risk is not judged against it at all.
What it would have been, over three years
Daily closes from 18 October 2023 to 4 September 2026. These are measurements of the past, on session closes; the 24/7 composite will read slightly higher volatility, so the real figures will sit a little below these.
| Median volatility, 30 days | Median limit | Lowest, and when | Time at the ceiling | |
|---|---|---|---|---|
| SPY | 12.4% | 80% | 68.2%, 9 April 2025 | 96% |
| GLD | 16.6% | 80% | 67.1%, 3 February 2026 | 78% |
| AAPL | 23.1% | 75% | 55.5%, 9 April 2025 | 72% |
| NVDA | 40.0% | 72.8% | 53.8%, 31 January 2025 | 13% |
| TSLA | 52.3% | 61.6% | 42.7%, 10 April 2025 | 3% |
| COIN | 71.8% | 58.4% | 40.0%, 6 November 2024 | 0% |
The tier grid is what a calm day looks like. On a lively stock, the calm day is rare.
How fast it moves
It falls quickly and comes back slowly, because the formula takes the larger of the seven-day and thirty-day readings. April 2025 on SPY, week by week:
| Date | Volatility 7 d | Volatility 30 d | Limit |
|---|---|---|---|
| 2 April | 16% | 20% | 80% |
| 9 April | 92% | 47% | 68.2% |
| 16 April | 39% | 50% | 76% |
| 1 May | 9% | 51% | 76% |
| 8 May | 14% | 43% | 77% |
| 15 May | 24% | 22% | 80% |
Twelve points lost in a week, eight recovered in a week, and five weeks to return to the ceiling. The thirty-day memory is what holds it down through the rebound, and that is deliberate.
The interface tells you which way it is heading. When the seven-day reading is above the thirty-day one, the limit is likely to rise in the coming days; when it is below, the opposite. It also tells you when the next recomputation is due.
What happens to a position you already hold
Nothing. A borrower who opened at the ceiling on a calm day and then watches volatility triple is not closer to being liquidated. The threshold did not move, the price did not move because of the recomputation, and the position is exactly where the market left it.
What changes is what you may do next:
| Action | While the limit is below your current ratio |
|---|---|
| Repay | Open, always |
| Add collateral | Open, always |
| Close | Open, always |
| Borrow more | Refused until your ratio clears the new limit |
| Withdraw collateral while repaying at least as much | Open: judged on your tier's ceiling, not on the day's limit |
| Withdraw collateral without repaying | Refused until the resulting ratio clears the day's limit |
Risk
A limit that falls does not protect a position opened before it fell. On 9 April 2025 a SPY position opened a week earlier at the ceiling was already 10.5% underwater and could be partially liquidated; the new limit only stopped anyone from opening a fresh position at the same place. The limit protects the next borrower, not the last one.
A branch that has just opened
A branch needs a real history before it can lend at its ceiling. Until half of the thirty-day window is covered, the protocol assumes a volatility of 25% on tier 1, 50% on tier 2 and 80% on tier 3, which puts the limit under the ceiling. A branch cannot even open until 15 days of that window are covered. Every hourly price reading on a dormant branch feeds that history, so the condition fills itself while the branch waits, with nobody running anything for it.
Rules R-19.16.1 to R-19.16.6, R-12.3.2
Can anyone push it around
Raising the volatility means moving the branch's reference price across the median of 3 readings inside one slot, which is the composite manipulation described on Price and oracle risk: on SPY that costs one to two million dollars of slippage and twenty to forty million of capital, held long enough to catch the majority of the readings, and it buys a fall of about two points of limit for seven days. Lowering it is not possible at all: a realised variance cannot be taken back out, and skipping a sample changes nothing because the formula weights by elapsed time.
A corporate action no longer clears the history either. A split or a dividend used to reset it, which pushed the limit onto its prior for a fortnight every time one happened; that is gone.
Rule R-19.16.6
Borrow
Deposit stock tokens, choose an amount and a rate, receive fyUSD. The two fields, the ratio you must clear, the fee, the caps, and the one risk number that matters.
Manage your position
Add collateral, repay, borrow more, withdraw, change your rate, close, claim a surplus — which of these can never be blocked, and which depend on the state of the branch.