Documentación / Conceptos de Bittensor / Cambios de protocolo
Shorts and longs on subnet alpha (PR #3268)
Lock TAO to short a subnet's alpha, or lock alpha to go long. Loans are lifted from the subnet's own pool when you borrow: 25% max loan, 100% annual interest burned, one-year term, no price liquidation.
Última revisión: 2026-10-30
Terms
| Term | Meaning |
|---|---|
| Pool | The subnet's swap pool, unchanged. |
| Lift | Taking TAO and alpha out of the pool in proportion, so the price doesn't move. It happens only when someone borrows; repaying puts it back. |
| Short | Lock TAO, borrow alpha. The chain sells the alpha at once and holds the TAO for you. |
| Long | Lock alpha, borrow TAO. The chain buys alpha with it at once and holds that alpha for you. |
| Raise | A long plus a sale of your own alpha in one call. The way a subnet team gets spendable TAO. |
| Collateral | What you lock: TAO for a short, alpha for a long. |
| Escrow | What the chain holds for you: the TAO from a short's sale, or the alpha from a long's buy. |
| Position | One open short or long. One per coldkey per subnet. |
| Reference price | A 24-hour moving average of the alpha price. |
Where loans come from
From the subnet's own pool, only when someone borrows. The chain lifts just enough TAO and alpha to cover the loan, in proportion, so the lift itself doesn't move the price. On repay, the same amounts go back into the pool with the pool's weights unchanged. Nothing is set aside in advance and no new tokens are created.
How much can be lent on a subnet depends on the pool's TAO, using the lower of the current value and its 24-hour average:
| Pool TAO | Total lending cap |
|---|---|
| Under 3,000 τ | 15% of the pool |
| 3,000 τ and up | At least 33% of the pool, up to 50% for the deepest pools |
Shorts and longs each get half the cap. Unused room on one side can't be used by the other.
A new subnet can't borrow for its first 50,400 blocks (about 7 days). The cap then ramps up linearly over 216,000 blocks (about 30 days).
Lending has a network-wide on/off switch that only root can set, and it starts off. Root also sets the parameters on this page, so treat the values below as defaults.
Rules
| Rule | Default |
|---|---|
| Max loan | 25% of collateral value. Longs on pools under 3,000 τ: 15% |
| Interest | 100% a year on the loan's opening value |
| Interest collected | Every 50,400 blocks (about weekly) |
| Where interest goes | The chain's burn address. Shorts pay TAO. Longs pay alpha, which the chain sells gradually before burning the TAO |
| Term | One year. The loan then settles automatically at the reference price. Adding to a loan restarts the year; a partial repay doesn't |
| Price-triggered liquidation | None |
| Opening limit | A long can't push the price more than 15% above the reference price, and a short can't push it more than 15% below. Closing and repaying are never blocked |
| Partial repay | Yes, on both sides |
| Slippage and deadline | Every call that trades takes a worst-acceptable amount and a last valid block |
| Minimum loan | 0.001 τ opening value |
| Max positions | 10,000 per subnet, 1,000,000 network-wide |
Long collateral is valued strictly. For the 25% check, the chain values your alpha at the lowest of the reference price, the current price, and what it would fetch if every other long's collateral on that subnet were sold first. The more longs a subnet has, the less each new long can borrow.
Long interest is sold slowly. Each block sells at most 0.01% of the pool's alpha. Sales pause while the price is more than 5% below the reference price, unless the backlog is older than four collection periods (about four weeks).
Burned TAO stays in total issuance. Interest is sent to the chain's standard burn address, which has no private key. It is not recycled, so total issuance doesn't fall.
Collateral and escrow earn nothing. Both sit on a lending custody hotkey that earns no emissions.
A short, step by step
| Step | What happens |
|---|---|
| Open | Lock TAO. The chain borrows alpha from the pool and sells it straight away. You never hold the alpha; the chain holds the TAO from the sale for you. |
| While open | Interest comes out of your TAO each collection period and is burned. |
| Close (default) | The chain uses the held TAO, then your collateral, to buy the alpha back. You get what's left. If the price has risen so far that this isn't enough, you pay the difference from your free TAO, up to your max_payment. |
| Close, other way | Repay the alpha from your own stake and take the held TAO. |
You profit if the price falls, because the buy-back costs less than the sale brought in. The sale at opening moves the price, so earlier shorts get a better price than later ones.
A long, step by step
| Step | What happens |
|---|---|
| Open | Lock alpha. The chain borrows TAO from the pool and buys alpha with it straight away. The chain holds that alpha for you. You receive no TAO. |
| While open | Interest comes out of your locked alpha each collection period. |
| Close (default) | The chain sells the held alpha, and as much collateral as needed, to repay the TAO. The rest of your alpha comes back to you as stake. |
| Close, other way | Repay the TAO from your wallet and take the held alpha. |
A long is a bet that the price rises. It is not a way to get TAO.
Raising TAO
A team that needs TAO uses open_long_and_sell. In one all-or-nothing call it:
- locks your alpha as collateral;
- opens a long, so the chain buys alpha with the borrowed TAO and holds it;
- sells the same amount of your other, unlocked alpha into the pool and sends you the TAO.
The buy and the sale offset each other, so the price ends close to where it started. Done as two separate trades, the buy alone would move the price first. You can later close the long to get back the held alpha and your collateral. If you walk away, you lose the collateral and the held alpha.
When collateral runs out
There is no liquidation on price. A loan ends early only when interest has used up its collateral. The chain then puts what it holds back into the pool.
When a subnet is deregistered
- New positions are allowed until the subnet is flagged for dissolution. Being the next prune candidate doesn't block them.
- Everything lifted goes back into the pool first.
- The chain fixes one settlement price from the pool's TAO, using the lower of the value at the flag and its 24-hour average, capped at the moving alpha price. A last-minute pump therefore can't raise it.
- Shorts owe the borrowed alpha at that settlement price and keep the rest of their held TAO and collateral. A short on a subnet that collapses pays back very little, so it profits.
- Longs repay the TAO from the value of their held alpha and collateral. If that isn't enough, they get nothing and the pool takes the shortfall.
- Unpaid interest is burned.
- All positions settle before alpha holders are paid out.
At 100% interest a year, a short only pays off if the fall comes soon enough to outweigh the interest.
Keys and proxies
- A coldkey swap moves your positions to the new coldkey. A hotkey swap doesn't touch lending.
- Proxies of type
Staking,NonTransferandAnycan open, close and repay.NonCriticalandNonFungiblecan't.open_long_and_sellneeds a proxy type that allows both opening a loan and removing stake.
btcli
bash
# Open a short: lock TAO, borrow alpha (the chain sells it for you).
btcli lending open --netuid 64 --side short --collateral 100 -w mywallet
# Open a long: lock alpha from a hotkey, borrow TAO (the chain buys alpha for you).
btcli lending open --netuid 64 --side long --collateral 700 --hotkey <hotkey> -w mywallet
# Close. Add --repay-from-wallet to repay a short with your own alpha,
# or a long with TAO from your wallet.
btcli lending close --netuid 64 -w mywallet
# Raise: lock alpha, borrow TAO, and sell your own alpha in one step.
btcli lending raise --netuid 64 --collateral 3000 --sell 2000 --hotkey <hotkey> -w mywallet
# List positions on a subnet, or one owner's position.
btcli lending list --netuid 64
btcli lending list --netuid 64 --coldkey <coldkey>What it means for Taostats data
- Positions: open, closed and expired positions, with collateral, amount owed, held TAO or alpha, interest burned and the end date. Raises show as a type of long.
- Per subnet: amount lifted, room left on each side, and whether new positions are blocked.
- Prices: opening a position trades in the pool at once. Charts need to separate lending trades from ordinary buys and sells.
- Stake: locked alpha moves to the lending custody hotkey. Label it as lending custody, not as a new staker.
- Burns: short interest (TAO) and long interest (alpha sold, then the TAO burned) are new burn sources. They show as transfers to the burn address, not as a drop in issuance.
- Deregistration: a settlement event per position, plus a subnet summary.
Source: PR #3268 (pallets/lending, runtime config, proxy filters, btcli lending) · Shorts and longs (Rufus)