Registration burn

Every subnet charges a single floating registration price, read live with burn. What happens to your payment is set by the subnet's collateral_lock_share (call it p):

• the (1 − p) share is burned — sunk, never refunded;
• the p share is locked as collateral — stake you earn back by mining, covered in registration collateral.

With p = 0 (the chain default) the whole price is burned, which is the classic burned registration this page describes. Everything here about how the price moves applies identically on collateral subnets — only the split of the payment changes.

How the price floats

Admission is governed entirely by price, with no registration windows:

• The price decays over time (update_registration_prices_for_networks), halving every burn_half_life blocks (default 360, about one tempo; owner-settable).
• Each successful registration multiplies the price (bump_registration_price_after_registration) by burn_increase_mult (default 1.26), so a registration rush gets expensive fast.
• The price is clamped between min_burn (default 500,000 rao = τ0.0005) and max_burn (default 100 TAO). All are per-subnet hyperparameters.

The result is price discovery: the price settles where the marginal registrant's willingness to pay meets supply. A miner who expects a registration slot to return X is willing to pay up to X for it, and the decay/bump dynamics float the price to that level. An idle subnet rests at exactly min_burn.

What the burned share buys (and where it goes)

The burned TAO is recycled, not staked — deregistering does not refund it. Under the hood (do_register), the TAO is swapped into the subnet's pool and the resulting alpha is removed from the subnet's outstanding supply.

Economically, the burn is the subnet's spam throttle. It prices the registration event itself: every attempt costs it, no matter how the attempt turns out, which is what keeps registration races and UID-lottery spam expensive. What the burn cannot do is price behavior after registration — a registered miner has nothing left at stake. That gap is what collateral exists to fill.

Worked example

Suppose netuid 42 has min_burn = τ0.5, burn_increase_mult = 1.26, burn_half_life = 360, and the price is currently τ1.00 with no collateral configured (p = 0):

1. You register and pay τ1.00. All of it is burned. The price immediately jumps to τ1.26 for the next registrant.
2. Two more miners register in the same tempo: they pay τ1.26 and τ1.59. The price is now τ2.00.
3. Nobody registers for the next 360 blocks: the price decays back to τ1.00, and after another 360 quiet blocks it would rest at min_burn's clamp path (τ0.5 floor).

Your τ1.00 is gone regardless of what happens next — if you are pruned in a week, re-registering costs whatever the price is then.

Owner controls

All owner-settable through btcli sudo set (rate-limited, and only outside the subnet's weights window):

btcli sudo set --netuid 42 --name min_burn --value 500000000        # rao
btcli sudo set --netuid 42 --name max_burn --value 100000000000     # rao
btcli sudo set --netuid 42 --name burn_half_life --value 360        # blocks
btcli sudo set --netuid 42 --name burn_increase_mult --value 1.26

• min_burn — the resting price of an idle subnet; keeps registration from becoming free. On collateral subnets this floors the total price, of which only (1 − p) is burned.
• max_burn — ceiling during registration rushes.
• burn_half_life — how fast the price cools; shorter half-life means cheaper re-entry after a rush.
• burn_increase_mult — how hard each registration pushes the price up; higher values throttle rushes more aggressively.

Related

Registration collateral, collateral_lock_share, burn query, burned-register