# alpha_low (/docs/hyperparameters/alpha-low)

`alpha_low` is the floor of the per-pair bonds EMA rate when [`liquid_alpha_enabled`](/docs/hyperparameters/liquid-alpha-enabled) is on. It is the rate applied to validator–miner pairs whose weights match consensus — the slow, steady end of the liquid-alpha range. Subnet owners tune it to set how sluggish bonds are in the default case; validators care because it governs how fast their conviction decays or accrues when they are not deviating.

## How it works [#how-it-works]

Each epoch, `alpha_sigmoid` (`pallets/subtensor/src/epoch/run_epoch.rs`) computes a per-pair rate:

```
alpha = alpha_low + sigmoid(diff) × (alpha_high − alpha_low)
```

where `diff` is the pair's deviation from consensus and the sigmoid rises with [`alpha_sigmoid_steepness`](/docs/hyperparameters/alpha-sigmoid-steepness). At zero deviation the sigmoid is near 0, so alpha sits at `alpha_low`; the result is always clamped into the `alpha_low`..`alpha_high` window. Defaults are (45875, 58982), i.e. 0.7 and 0.9 of `u16::MAX`.

Validation in `do_set_alpha_values`: liquid alpha must already be enabled (`LiquidAlphaDisabled`), `alpha_low` must be at least 1638 (`u16::MAX / 40` ≈ 0.025) and at most `alpha_high`, else `AlphaLowOutOfRange`.

<HyperparamLiquidAlpha focus="alpha_low" />

## Reading and setting [#reading-and-setting]

```
btcli sudo get --netuid N --name alpha_low
```

Stored as u16 (65535 = 1.0); the CLI accepts the raw integer or a 0..1 fraction with a decimal point:

```
btcli sudo set --netuid N --name alpha_low --value 0.7
```

On chain, `alpha_low` and [`alpha_high`](/docs/hyperparameters/alpha-high) live in one storage value set by a single `sudo_set_alpha_values` call. The CLI reads the current pair and resubmits it with only `alpha_low` changed, so the other side is preserved.

## Related [#related]

[`alpha_high`](/docs/hyperparameters/alpha-high), [`alpha_sigmoid_steepness`](/docs/hyperparameters/alpha-sigmoid-steepness), [`liquid_alpha_enabled`](/docs/hyperparameters/liquid-alpha-enabled), [`bonds_moving_avg`](/docs/hyperparameters/bonds-moving-avg), [`yuma3_enabled`](/docs/hyperparameters/yuma3-enabled)