Aquarius AMM Explained: Stellar's Liquidity Layer

What is the Aquarius AMM?

Aquarius is Stellar's liquidity-incentive protocol. It runs on top of Stellar's native constant-product AMM pools and adds AQUA emissions on top of trading fees. Holders lock AQUA for ICE voting power and vote to direct those emissions toward specific pools, so the most-voted markets earn the most rewards.

It helps to separate two things people lump together. Stellar itself has native AMM pools at the protocol layer — a pool is a base-network object, not a smart contract someone deployed. Anyone can open a two-asset pool and it will price swaps automatically. That is the "AMM" part.

Aquarius, launched in 2021, is the incentive layer that sits above those pools. It issues the AQUA token, runs an emissions schedule, and lets the community decide which pools those emissions flow to. So when people say "the Aquarius AMM," they usually mean native Stellar pools plus the AQUA rewards Aquarius routes to them. For the token side of the story, see What Is the AQUA Token? and the broader map in our Stellar DeFi guide.

How a constant-product AMM works

A constant-product AMM prices trades with the formula x*y=k, where x and y are the two pool reserves and k stays constant. Buying one asset removes it from the pool and adds the other, moving the price along a curve. The bigger a trade is relative to the pool, the more the price slips.

An AMM replaces a human order book with a formula. Instead of matching buyers to sellers, a pool holds a reserve of two assets and quotes a price from their ratio. The classic design is constant-product: the product of the two reserves must stay the same before and after every trade.

Say a pool holds 1,000 of Token A and 1,000 of Token B. Then k = 1,000 × 1,000 = 1,000,000. If you buy some Token A, you add Token B and remove Token A, but the product must still equal 1,000,000 — so the price of each remaining Token A rises. Three consequences fall out of this one rule:

• Price is set by ratio, not by an order book. There is always a quote, even with no counterparty waiting.
• Slippage grows with trade size. A trade that is small relative to the reserves barely moves the price; a large one moves it a lot.
• Arbitrage keeps pools honest. If the pool price drifts from the wider market, traders arbitrage it back, and those trades pay fees to liquidity providers.

Every swap also pays a small fee into the pool, which is what makes supplying liquidity worthwhile in the first place.

The liquidity-incentive layer

On its own, an AMM pool only pays trading fees. Aquarius adds a second reward stream: AQUA emissions. Lockers convert AQUA into ICE, non-transferable voting power, and vote each epoch to direct emissions to pools. Pools that attract the most votes receive the most AQUA, so votes decide where liquidity incentives flow.

This is the mechanism that makes Aquarius more than a plain AMM. The flow works like this:

1. Lock AQUA → get ICE. Locking AQUA mints ICE, a non-transferable voting weight. Longer locks generally carry more weight.
2. Vote ICE toward pools. Each epoch, ICE holders vote for the pools they want emissions to reach.
3. Emissions follow the votes. Aquarius distributes AQUA to pools in proportion to the votes they receive.
4. Bribes sweeten the deal. Projects that want liquidity in their pool can offer "bribes" — extra rewards paid to voters who back it.

The result is a market for liquidity: emissions and bribes shift every epoch toward whoever the voters favour. We break the voting and bribe economics down in ICE Voting & Bribes on Aquarius, and the general pattern of earning rewards for supplying liquidity in What Is Liquidity Mining?.

How liquidity providers actually earn

Liquidity providers earn two ways on Aquarius: a share of the swap fees every trade pays into the pool, and AQUA emissions directed to that pool by ICE voters. Your share is proportional to how much of the pool you supply. The trade-off is impermanent loss if the two assets diverge in price.

When you deposit into a pool you receive pool shares representing your slice of the reserves. Those shares entitle you to two income streams:

• Trading fees. A cut of every swap, paid continuously and in proportion to your share of the pool.
• AQUA emissions. If ICE voters have directed emissions to your pool, you collect a proportional slice of that AQUA on top of the fees.

The catch: impermanent loss

Providing liquidity is not risk-free. Because arbitrage constantly rebalances a constant-product pool, when the two assets diverge in price you end up holding more of the one that fell and less of the one that rose — worse than if you had simply held both in your wallet. That gap is impermanent loss. Fees and AQUA emissions can offset it, and sometimes more than cover it, but not always. It is the single most important concept to understand before you LP; we cover it in depth in What Is Liquidity Mining?. For the live numbers, always check the current APY on the app rather than assuming a fixed rate.

Aquarius vs the SDEX order book

Stellar gives you two ways to trade and provide liquidity: the built-in order book (SDEX) and Aquarius AMM pools. They solve the same problem differently.

Neither is strictly better. The order book suits active traders who want price control; Aquarius pools suit anyone who wants to supply liquidity once and earn passively — especially with AQUA emissions stacked on top.

A glass-box worked example

Adding liquidity means depositing both assets in the pool's current ratio and receiving pool shares in return. Those shares track your proportional claim on the reserves, the fees they accrue, and any AQUA emissions the pool receives. Redeem the shares later to withdraw your assets plus earned fees.

Here is the mechanism end to end, with round numbers chosen only to make the math legible — not a quoted return:

Pool before you join
  Reserves:  10,000 AQUA  +  10,000 XLM
  Constant:  k = 10,000 × 10,000 = 100,000,000

You add liquidity (must match the current 1:1 ratio)
  Deposit:   1,000 AQUA  +  1,000 XLM
  New pool:  11,000 AQUA  +  11,000 XLM
  Your share = 1,000 / 11,000 ≈ 9.09% of the pool

While you're in the pool
  1. Traders swap against the pool → fees accrue to all shares
  2. If ICE voters directed AQUA emissions here → you earn AQUA too
  3. Both accrue in proportion to your 9.09% share

If AQUA and XLM diverge in price
  Arbitrage rebalances the reserves along x*y=k
  → you end up holding more of the weaker asset
  → this gap vs. just holding = impermanent loss

You withdraw
  Redeem your 9.09% of shares
  → receive your share of the (now-rebalanced) reserves
  → plus accumulated fees + any AQUA emissions

The takeaways: you always deposit in the pool's current ratio, your rewards scale with your share, and impermanent loss is the price of admission for earning fees and emissions. Whether the net result is positive depends on trading volume, how much AQUA the pool is voted, and how far the two assets drift.

Where WhaleHub fits

WhaleHub aggregates ICE voting power from all its stakers and votes it toward high-yielding Aquarius markets each epoch. It claims the AQUA rewards and bribes those votes earn, then auto-compounds them for depositors — so users capture Aquarius incentives without managing votes or claims themselves.

The friction in earning on Aquarius is not the AMM — it is the incentive layer. To capture the best emissions you have to lock AQUA for ICE, track which market is hottest each epoch, vote every cycle, then claim and re-invest the rewards. A small holder's ICE barely moves a vote, and the claim-and-restake grind eats into any gain.

WhaleHub, often described as "Convex for Stellar," solves both problems by pooling. It aggregates ICE from every staker into whale-tier voting weight, points it at the highest-yielding markets, and lets the backend claim rewards roughly every 30 minutes, swap them to BLUB, and distribute them proportionally. Rewards also feed back into more ICE and protocol-owned liquidity, so the voting power compounds over time.

When you stake AQUA, WhaleHub mints BLUB to your staking balance one-for-one as a liquid receipt — a floating derivative of your staked position whose value is set by the market, not redeemable for AQUA. From there the votes, claims, and compounding happen for you. If you want the step-by-step, start with How to Stake AQUA.

---

Aquarius is best understood in two layers: a native constant-product AMM that turns two-asset pools into an always-on market, and an incentive system that pays AQUA to whichever pools the community votes for. Provide liquidity and you earn fees plus emissions — minus impermanent loss. Do it through an optimizer and the voting and compounding stop being your job.