Conviction

1. What is conviction?

Conviction is Bittensor's governance mechanism that ties voting power to long-term commitment. When you lock alpha tokens to a subnet, you earn conviction — a measure of your stake's weight in governance decisions and subnet ownership.

Conviction exists to:

• Reward long-term alignment over short-term speculation
• Provide subnet governance stability
• Enable subnet ownership transitions through the subnet king mechanism
• Create skin-in-the-game for validators and subnet owners

Locks are perpetual by default, subnet owners receive instant conviction, and the unlock queue was eliminated in favor of exponential decay.

2. How locking works

To earn conviction, you lock alpha tokens using the lock_stake extrinsic:

• One lock per coldkey per subnet — You can only have a single active lock targeting one hotkey on each subnet.
• Lock to a hotkey — Your locked alpha is associated with a specific hotkey on that subnet. This is typically the subnet owner's hotkey, or the hotkey of someone building conviction to challenge for subnet ownership.
• Top-ups must match — Additional locks to the same subnet must target the same hotkey; you can't split locks across multiple hotkeys.
• Perpetual by default — Locked mass stays constant indefinitely, allowing conviction to grow toward 100%.
• Optional decay — Call set_perpetual_lock(false) to enable exponential decay if you want to eventually unstake.

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Conviction locking and staking are separate — you can do both with the same alpha

Conviction locking (via lock_stake) and regular staking are different methods and don't have to point at the same hotkey. You can lock to the subnet owner's hotkey to build conviction and show support for the owner, while staking the same alpha to a different, higher-performing hotkey (for example, a Taostats validator). That way you maximize your alpha staking rewards and keep your conviction directed at the owner.

3. Two types of locks

Perpetual locks (default)

When you lock alpha without toggling decay, your lock is perpetual:

• locked_mass remains constant forever
• conviction grows exponentially from 0 toward locked_mass
• Conviction asymptotically approaches 99% after 1 year, 99.9%+ after 2 years
• Cannot unstake — perpetual locks stay locked unless you toggle to decaying mode

Decaying locks

After calling set_perpetual_lock(false), your lock begins exponential decay:

• locked_mass decays with UnlockRate (158.6 day time constant)
• conviction follows a coupled decay/growth formula driven by MaturityRate (79.3 day time constant)
• After 365 days, 90% of locked mass has decayed (by design)
• You can unstake the difference between your original lock and current locked_mass

Subnet-owner locks

Subnet owners receive special treatment:

• Instant conviction — conviction equals locked_mass immediately (no growth period)
• Auto-locked owner cut — The owner's share of emissions is automatically locked each block, building conviction continuously
• Owner locks are perpetual by default but can opt into decay

4. The numbers

System parameters

Conviction growth timeline (perpetual lock)

How conviction grows over time when locked_mass stays constant:

Locked-mass decay timeline (decaying lock)

How locked_mass decays after toggling set_perpetual_lock(false):

5. Worked example

Scenario: a validator locks 10,000 alpha on subnet 64 to their hotkey.

Phase 1: perpetual lock (default)

locked_mass = 10,000 alpha (constant)

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Perpetual locks cannot be unstaked. Locked mass stays at 10,000 alpha forever.

Phase 2: toggle to decaying

At day 365, the validator calls set_perpetual_lock(false). Now both locked_mass and conviction evolve:

Unstakeable amount = original lock (10,000) − current locked_mass.

After 1 year of decay, the validator can unstake 9,000 alpha, leaving 1,000 still locked.

6. Subnet-owner locks

Subnet owners accumulate locked alpha automatically and receive immediate conviction:

• Owner cut auto-locked: Each block, the owner's emissions share is locked to their subnet ownership hotkey.
• No initial alpha distribution: Subnet registration does not distribute initial alpha to the owner. Conviction builds solely through the auto-locked owner cut from ongoing emissions.
• Instant conviction: Unlike validators, owners don't wait for conviction to grow — conviction = locked_mass immediately.
• Perpetual by default: Owner locks don't decay unless the owner explicitly calls set_perpetual_lock(false).
• Aggregate tracking: All owner locks on a subnet are aggregated into OwnerLock storage for subnet king calculations.

This instant conviction ensures subnet owners always have governance weight proportional to their locked stake without waiting periods.

7. Subnet king mechanism

After a subnet has been active for 1 year (365.25 days), ownership can transfer via the subnet king mechanism.

Eligibility requirements

• Subnet must be at least 365.25 days old.
• A single hotkey's own rolled aggregate conviction must exceed 18% of eligible alpha, where eligible alpha = SubnetAlphaOut − SubnetProtocolAlpha − AlphaBurned. The subtraction saturates at zero, so a subnet with zero eligible alpha can never transfer ownership. The bar is measured on the winning hotkey alone — the subnet-wide total no longer counts, so other keys' locks (including the incumbent owner's) do not add to a challenger's threshold.
• The hotkey with the highest aggregate conviction is the candidate, and that same hotkey must clear the 18% bar by itself. Conviction is aggregated per hotkey (from all coldkeys locking to that hotkey), not per coldkey.

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Reading eligible alpha from the API

You don't have to compute SubnetAlphaOut − SubnetProtocolAlpha − AlphaBurned yourself. The Taostats dTAO pool endpoint exposes this exact quantity as the alpha_staked field (GET /api/dtao/pool/latest/v1?netuid=<n>). To check how close a subnet is to a takeover, compare a hotkey's rolled conviction against 0.18 × alpha_staked.

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Changed in runtime spec 447

Before spec 447, ownership transferred once the subnet-wide total rolled conviction (all hotkeys and coldkeys combined, including the owner) reached 10% of eligible alpha. Spec 447 replaced that with an 18% bar on a single hotkey's own conviction. Summing across all lockers let unrelated stakers — the incumbent owner included — inadvertently supply a challenger's quorum; gating on the winner's own conviction closes that path. Coalitions still work because backers lock directly to the challenger's hotkey, so their conviction lands in that hotkey's aggregate.

How it works

1. Aggregate calculation: For each hotkey, the system sums rolled conviction across all locks targeting it — HotkeyLock + DecayingHotkeyLock + OwnerLock (and the decaying owner lock) — via a single shared computation (subnet_king_with_conviction), so selection and the admission gate can never disagree.
2. Comparison: The hotkey with the highest aggregate conviction is the subnet king candidate. Ownership transfers only if that hotkey's own conviction exceeds 18% of eligible alpha — the subnet-wide sum is not used. The comparison is cross-multiplied in 256-bit integers so high-range takeovers can't saturate.
3. Transfer: Ownership transfers, and the lock aggregates swap:
   • Old owner's OwnerLock → becomes non-owner locks
   • New owner's non-owner locks → become OwnerLock
4. Instant conviction retained: The new owner keeps their conviction value but now has instant-conviction status for future locks.

Design rationale: This mechanism prevents permanent ownership monopolies while requiring challengers to demonstrate long-term commitment through locked alpha and conviction growth.

8. What you can and can't do

✅ Allowed actions

• Top up existing lock: Add more alpha to your existing lock (must target the same hotkey).
• Move lock to a different hotkey: You can move your lock to a different hotkey on the same subnet. If the destination hotkey is owned by the same coldkey, conviction is preserved. If owned by a different coldkey, conviction resets to zero.
• Toggle decay mode: Switch between perpetual and decaying at any time with set_perpetual_lock.
• Partial unstaking (decaying only): Unstake the difference between original lock and current locked_mass.

❌ Not allowed

• Unstake perpetual locks: You must first toggle to decaying mode and wait for mass to decay.
• Cross-subnet transfers: Locks are subnet-specific and cannot be moved between subnets.
• Multi-hotkey locks: You cannot have multiple locks to different hotkeys on the same subnet from one coldkey.
• Lock hotkey changes: If you have an active lock on a subnet, you can't lock to a different hotkey without first removing the existing lock.
• Coldkey swap with active locks on destination: A coldkey swap requires the destination coldkey to have no active locks. The source coldkey's locks transfer to the destination, but only if the destination is clean.

9. Technical reference

Storage maps

LockState structure

LockState {
  locked_mass: u64,   // Current locked alpha (decays if non-perpetual)
  conviction: u64,    // Governance weight (grows/decays based on mode)
  last_update: u64    // Block number of last state update
}

Roll-forward formula

When reading lock state, the system rolls forward from last_update to the current block. With dt = current_block − last_update blocks elapsed, the decay factors and coupling term are:

The locked mass either holds (perpetual locks) or decays:

For subnet owners with instant conviction, the formula simplifies to conviction = locked_mass (no roll-forward needed for conviction growth).

Key extrinsics

• lock_stake(hotkey, netuid, amount) — Lock alpha to a hotkey on a subnet (perpetual by default).
• set_perpetual_lock(netuid, perpetual: bool) — Toggle between perpetual (true) and decaying (false) mode.