# What is a Cardano stake pool?

> A Cardano stake pool is a block-producing operation that ADA holders delegate their stake to. The protocol rewards it for the blocks it mints; the operator first takes a fixed cost of at least 170 ADA per epoch and a percentage margin, and the rest is shared among delegators by stake. Pledge, saturation and pool size also change what delegators receive.

**In one line:** A pool's fixed cost, margin, pledge and size decide how much of its rewards reach you; read them before you delegate.

A Cardano [stake pool](/yield/glossary#stake-pool) is a block-producing operation that ADA holders [delegate](/yield/glossary#delegation) their stake to, without transferring any ADA. The protocol rewards the pool for the blocks it mints; the operator first takes a [fixed cost](/yield/glossary#fixed-cost) of at least 170 ADA per epoch and then a percentage [margin](/yield/glossary#margin), and the remainder is shared among delegators in proportion to stake. The Gatewayz pool is an ordinary stake pool with its margin set near 100%.

## Key takeaways

- A [stake pool operator](/yield/glossary#stake-pool-operator) runs the nodes and declares three numbers: fixed cost, margin and pledge.
- Rewards are split in order: fixed cost, then margin, then the remainder to all delegators by stake, including the pool owners.
- If the owners delegate less than the declared [pledge](/yield/glossary#pledge), the pool's rewards for that epoch are zero.
- Past [saturation](/yield/glossary#saturation), roughly 77.9 million ADA in epoch 664, extra stake lowers rewards per ADA for everyone in the pool.
- Small pools mint blocks less often, so their rewards vary more from epoch to epoch.

## What does a stake pool operator do?

The operator runs the infrastructure that produces blocks for the stake delegated to the pool, and sets the pool's parameters. In general terms, a pool runs a block-producing node, which creates blocks when the pool is elected, and relay nodes, which connect it to the rest of the network.

The protocol elects block producers from a [stake snapshot](/yield/glossary#stake-snapshot), so a pool with more active stake is elected more often. A pool that is offline when elected misses that block and the rewards that come with it. The operator never holds delegators' ADA: delegation is a certificate on each holder's own [stake key](/yield/glossary#stake-key).

## What are fixed cost and margin?

They are the operator's two fees, taken before delegators are paid. The fixed cost is a flat amount of ADA per epoch; the protocol minimum is currently 170 ADA (minPoolCost 170,000,000 [lovelace](/yield/glossary#lovelace)). The margin is a percentage of what is left after the fixed cost.

Together they make up the pool's [pool fees](/yield/glossary#pool-fees). Rewards are split in a fixed order: declared costs to the operator first, then the declared margin, then the remainder in proportion to delegated stake among all delegators, including the pool owners.

## What is pledge, and why can it zero a pool's rewards?

Pledge is ADA the pool's owners commit to their own pool. It matters in two ways. Through the a0 parameter (live value 0.3), pools with meaningful pledge earn slightly more than pools with the same total stake and no pledge. And pledge is a promise the protocol enforces: if the owners collectively delegate less than the declared pledge, the pool's rewards for that epoch are zero, for the operator and every delegator.

## What is saturation?

Saturation is the stake level beyond which a pool's rewards stop growing. The saturation point is total stake divided by the [k parameter](/yield/glossary#k-parameter), whose live value is 500; in epoch 664 that is roughly 77.9 million ADA. Past that point, extra delegation does not increase the pool's rewards, so rewards per ADA drop for everyone in it. That cap is how k sets the target number of saturated pools.

## Why do small pools' rewards vary more?

Because they are elected less often. In Cardano.org's words, small pools mint blocks less often, so their rewards vary more from epoch to epoch. A small pool can go a whole epoch without a block, and an epoch with no blocks has nothing to share.

## How do you read a pool's parameters?

Look at five numbers before delegating. Each tells you something different about what reaches you.

| Parameter | What it tells you | What to check |
| --- | --- | --- |
| Fixed cost | ADA taken per epoch before anything else | At least 170 ADA; higher costs weigh more on small pools |
| Margin | Share of the remainder the operator keeps | 0% to 100%; near 100% means delegators receive almost no ADA |
| Pledge | ADA the owners commit | Owners must actually delegate at least this much, or rewards are zero |
| Active stake vs saturation | How full the pool is | Compare with roughly 77.9 million ADA (epoch 664) |
| Blocks minted | Whether the pool is producing | A small pool may have epochs with none |

## Worked example: how is one epoch's reward split?

This example uses **illustrative round numbers**, not data from any real pool. Assume a pool's rewards for one epoch are 10,000 ADA and you hold 1% of the pool's stake. Compare a low-margin pool (illustrative 2%) with a near-100%-margin pool like the Gatewayz pool (99% margin plus the 170 ADA minimum fixed cost).

| Step | Low-margin pool (2%) | Near-100%-margin pool (99%) |
| --- | --- | --- |
| Pool rewards for the epoch | 10,000 ADA | 10,000 ADA |
| Fixed cost to operator | 170 ADA | 170 ADA |
| Remainder after fixed cost | 9,830 ADA | 9,830 ADA |
| Margin to operator | 196.6 ADA (2%) | 9,731.7 ADA (99%) |
| Pool fees (fixed cost + margin) | 366.6 ADA | 9,901.7 ADA |
| Left for all delegators | 9,633.4 ADA | 98.3 ADA |
| **Your 1% in ADA rewards** | **96.33 ADA** | **0.98 ADA** |

In the low-margin pool, nearly all of the rewards reach delegators as ADA. In the near-100%-margin pool, delegators receive almost nothing in ADA, because the pool keeps the rewards as fees.

With Gatewayz, those fees are what funds the discount. Gatewayz takes 95% of what it actually received for the epoch and multiplies it by your share of the pool's stake: 95% of 9,901.7 ADA is 9,406.6 ADA, and your 1% is about 94.07 ADA of value, converted to USD at the ADA price when it is recorded and credited to your [inference discount balance](/yield/glossary#inference-discount-balance). That balance pays 99% of each request's list price on Gatewayz while it lasts; it is not ADA and cannot be withdrawn. Real pools earn different amounts every epoch, and launch limits cap the discount per account per day.

Launch limits: at most $5 of discount per account per day, and at most $50 per day across the whole program. Limits may change.

[Staking rewards vs an inference discount](/yield/learn/staking-rewards-vs-inference-discount) runs the same comparison with real network inputs, and [How it works](/yield/how-it-works) explains the daily accounting.

## Frequently asked questions

### Does a stake pool hold my ADA?

No. Delegation assigns your stake to a pool with a certificate on your stake key, and your ADA stays in your own wallet. The operator cannot move it.

### What is the minimum fixed cost for a Cardano stake pool?

The protocol minimum is currently 170 ADA per epoch, set by the minPoolCost parameter at 170,000,000 lovelace. A pool may declare a higher fixed cost but not a lower one.

### What happens if a pool does not meet its pledge?

Its rewards for that epoch are zero. If the pool owners collectively delegate less than the pledge they declared, neither the operator nor the delegators receive rewards for that epoch.

### Why would anyone delegate to a pool with a near-100% margin?

Because the pool may return value another way. The Gatewayz pool keeps nearly all rewards as fees and turns 95% of what it received into an inference discount for linked delegators. It suits people who spend on AI; anyone who wants ADA rewards should choose a low-margin pool.

### Is a bigger pool always better?

No. A larger pool mints blocks more regularly, which smooths rewards, but past the saturation point of roughly 77.9 million ADA (epoch 664) extra stake lowers rewards per ADA for everyone in that pool.

## Sources

- [Cardano Docs: Pledging and rewards](https://docs.cardano.org/about-cardano/learn/pledging-rewards), as of 2026-10-27
- [Cardano.org Glossary: Minimum Pool Cost](https://cardano.org/glossary/min-pool-cost/), as of 2026-10-27
- [Cardano.org: Stake your ada on Cardano](https://cardano.org/stake-pool-delegation/), as of 2026-10-27
- [Cardano.org Glossary: Pledge](https://cardano.org/glossary/pledge/), as of 2026-10-27
- [Cardano.org Glossary: k parameter](https://cardano.org/glossary/k-parameter/), as of 2026-10-27
- [Koios API: totals (epoch 664)](https://api.koios.rest/api/v1/totals?_epoch_no=664), as of 2026-10-27
- [Cardano.org Glossary: Pool Saturation](https://cardano.org/glossary/pool-saturation/), as of 2026-10-27
- [Cardano.org Glossary: Stake Snapshot](https://cardano.org/glossary/stake-snapshot/), as of 2026-10-27
- [Cardano.org Glossary: Delegation](https://cardano.org/glossary/delegation/), as of 2026-10-27

## Related

- [How Cardano staking works](https://www.gatewayz.ai/yield/learn/how-cardano-staking-works)
- [Staking rewards vs an inference discount](https://www.gatewayz.ai/yield/learn/staking-rewards-vs-inference-discount)
- [Stake ADA without giving it up, and pay for AI with the rewards](https://www.gatewayz.ai/yield/assets/ada)
- [How yield-as-inference works](https://www.gatewayz.ai/yield/how-it-works)
- [The risks of ADA delegation with Gatewayz](https://www.gatewayz.ai/yield/risks)

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Discounts are a share of staking rewards Gatewayz actually received, can change at any time, and are not a guaranteed return. Not available to US or Canadian persons. Every participant must confirm they are not a US or Canadian person before linking a wallet. Not investment, legal or tax advice. Figures as of 2026-10-27.

Updated 2026-10-27. Canonical page: https://www.gatewayz.ai/yield/learn/cardano-stake-pools-explained