Alpha Low
Alpha low is the lower bound of the liquid alpha range, the pair of values that set how quickly
validator-miner bonds
smooth when the liquid alpha feature is enabled. The
Subnet Hyperparameters reference
describes the alpha range as being set through AlphaValues via the alpha_low and alpha_high
parameters.
What It Sets
Liquid alpha varies the bond-smoothing factor by how well a validator’s weights align with consensus, instead of holding that factor constant. Alpha low is the floor of that variable factor: it caps how slow the smoothing can get at one end of the alignment range (Consensus-based Weights).
The smoothing factor, often written as an EMA coefficient, controls how much each epoch’s bond update weighs new information against the prior bond. Alpha low pins the bottom of the allowed range for that coefficient (EMA).
When liquid alpha is disabled on a subnet, alpha low does not shape bond updates on that path. Bond smoothing then follows the stored bonds moving average rather than the liquid-alpha floor, so the same hyperparameter table can produce different bond behavior depending on whether liquid alpha is active (Consensus-based Weights, Subnet Hyperparameters, Yuma Consensus: Bonding mechanics).
Documented Setter
There is no standalone setter for alpha low on its own. The reference documents the bounds under the
combined AlphaValues hyperparameter, which is changed through the sudo_set_alpha_values
extrinsic, exposed in tooling as btcli sudo set --param sudo_set_alpha_values, with the permission
required to set it marked as subnet owner
(Subnet Hyperparameters).
The constants reference also fixes the documented default for this lower bound as
api.consts.subtensorModule.alphaLow, listed as 45875 — the u16 form of approximately 0.7 once
divided by the 65535 scale. That constant names the network default endpoint, while the live
alpha_low in force is per-subnet chain state supplied through the paired AlphaValues update
(Subtensor Constants: alphaLow,
Subnet Hyperparameters).
Because the two bounds are written together, the documentation states that modifying AlphaValues
requires supplying both the alpha_low and alpha_high values for the subnet. A change to the
lower bound is therefore submitted as a paired update of the whole range rather than as an isolated
edit to one endpoint
(Subnet Hyperparameters).
In the btcli hyperparameter listing, alpha_low appears as an owner-settable row described as the
low bound of the alpha range for stake calculations, which is the same lower endpoint the combined
AlphaValues setter writes. The companion alpha_high row carries the matching high-bound
description, so the two table entries are the readable view of one paired setting
(Subnet Hyperparameters).
The live alpha_low and alpha_high in force on a subnet are per-netuid chain state, so any
real-time value is tied to a specific netuid. For the documented example netuid 1 on Finney mainnet,
both bounds can be read from that subnet’s hyperparameter table with
btcli subnet hyperparameters --netuid 1 --network finney, which keeps the paired setting
reproducible against a parseable netuid
(Subnet Hyperparameters: View hyperparameters).
Distinction from Alpha High
Alpha low and alpha high are the two ends of the same range. Alpha low sets the lower bound of the bond-smoothing factor, while alpha high sets the upper bound; together they bracket how far liquid alpha may move the factor (Subnet Hyperparameters).
- Alpha low — the lower bound of the smoothing factor.
- Alpha high — the upper bound of the smoothing factor.
Distinction from Liquid Alpha
Liquid alpha is the feature that makes the bond-smoothing factor vary by consensus alignment, while alpha low is one of the two bound values that feature uses. The feature decides that the factor varies; alpha low decides how low it may go (Consensus-based Weights).
- Liquid alpha — feature that varies bond smoothing by consensus alignment.
- Alpha low — lower bound that caps how low the smoothing factor may go.
Distinction from Alpha Sigmoid Steepness
Alpha low and alpha sigmoid steepness both shape the liquid alpha response but in different ways. Alpha low is the lower endpoint of the range the bond-smoothing coefficient may take, while alpha sigmoid steepness sets how sharply the coefficient moves across that range as a validator’s consensus alignment changes (Subnet Hyperparameters, Consensus-based Weights, Glossary: Validator-Miner Bonds).
The bounds fix where the coefficient can land; steepness sets how abruptly it travels between them.
- Alpha low — the lower endpoint of the coefficient range.
- Alpha sigmoid steepness — how sharply the coefficient moves across that range.
Distinction from Bonds Moving Average
Alpha low and bonds moving average are different bond-smoothing controls. Alpha low is one endpoint
of the liquid alpha range — the floor of the variable coefficient that varies bond smoothing by
alignment — while bonds moving average is the documented BondsMovingAverage hyperparameter that
configures the moving-average behavior applied to validator-miner bonds. One bounds a
consensus-aligned variable factor; the other configures the underlying bond smoothing
(Subnet Hyperparameters,
Yuma Consensus).
- Alpha low — the lower bound of the liquid-alpha variable coefficient.
- Bonds moving average — the hyperparameter configuring the bond moving-average behavior.
Distinction from Bonds Penalty
Alpha low and bonds penalty are separate bond-path Yuma Consensus hyperparameters. Alpha low sets the floor of the liquid-alpha smoothing coefficient, while bonds penalty sets the magnitude of the penalty applied when a validator’s weights exceed the subnet consensus benchmark. One governs how slowly bonds may adapt; the other governs how out-of-consensus weights are penalized on the bond path (Subnet Hyperparameters, Yuma Consensus).
- Alpha low — the lower bound of the bond-smoothing coefficient.
- Bonds penalty — the penalty magnitude for out-of-consensus weights.
Chain Reads for netuid 1
Readers can verify live hyperparameter values for the documented example netuid with
btcli subnet hyperparameters --netuid 1 --network finney
(Subnet Hyperparameters: View hyperparameters).
That read path keeps live hyperparameter claims tied to a parseable netuid.
Per-Subnet Live Value Boundary
Alpha low is per-subnet chain state. The lower bond-smoothing bound configured on one netuid applies only inside that subnet’s liquid-alpha path, but the live floor can differ from reference defaults and from alpha low on another netuid (Subnet Hyperparameters, Consensus-based Weights).
This article’s infobox uses netuid 1 as an example label when reading alpha curve settings on one subnet. That example helps readers verify one table; it is not proof that every subnet exposes the same live floor (Bittensor Networks).
Alpha low governs bond-smoothing bounds when liquid alpha is enabled; Yuma Consensus still settles validator weights into emission shares each epoch (Yuma Consensus).
- Alpha low — lower bound for liquid-alpha bond smoothing on a subnet.
- Per-subnet boundary — live value is chain state on one netuid.
Distinction from Yuma Consensus
Alpha low is a per-subnet hyperparameter that sets the lower bound used in liquid-alpha bond smoothing inside Yuma Consensus. Yuma Consensus is the separate mechanism that applies bonding, clipping, and dividend logic when settling miner and validator shares each epoch (Subnet Hyperparameters, Consensus-based Weights, Yuma Consensus, Emission).
- Alpha low — lower bound for liquid-alpha bond smoothing.
- Yuma Consensus — on-chain settlement that turns validator weights into emission shares. Alpha low names bond-smoothing bounds; Yuma processes validator weights into rewards (Yuma Consensus: Validator emissions).
Reader Boundary
This page defines alpha low at a high level. It does not report the live alpha_low value on any
particular subnet or whether liquid alpha is enabled there. Those are per-subnet hyperparameter
settings that should be checked for the relevant netuid
(Subnet Hyperparameters).