An Automated Market Maker (AMM) is a foundational technology in Decentralised Finance (DeFi) that enables the trading of digital assets without traditional order books or intermediaries. Instead of matching buyers and sellers, AMMs use mathematical algorithms and pools of cryptocurrency funds (liquidity pools) to automatically determine asset prices and execute trades.
How it works
At its core, an AMM operates using a constant product formula, the most common being x * y = k. Here, 'x' and 'y' represent the quantities of two different tokens in a liquidity pool, and 'k' is a constant. This formula ensures that the product of the two token reserves always remains the same. When a trader wants to swap one token for another, they add one token to the pool and remove the other, which alters the ratio of the tokens. To maintain the constant 'k', the price of the asset being bought increases, and the price of the asset being sold decreases, effectively reflecting supply and demand within that specific pool.
Liquidity providers (LPs) are crucial to AMMs. They deposit pairs of tokens into these pools, earning a share of the trading fees generated by the swaps. By contributing liquidity, LPs provide the necessary capital for trades to occur. Without sufficient liquidity, slippage (the difference between the expected price and the execution price) can become significant, especially for larger trades, making the pool less attractive. Different AMM designs, such as those employing concentrated liquidity, aim to improve capital efficiency and reduce slippage for LPs and traders alike.
Why it matters for Australian investors
For Australian crypto investors, AMMs unlock opportunities otherwise unavailable through traditional finance. They provide access to a vast array of digital assets, including smaller, innovative projects not listed on centralised exchanges, and often at competitive trading fees. The ability to become a liquidity provider allows investors to earn passive income from their idle crypto assets, aligning with diverse investment strategies. Furthermore, the decentralised nature of AMMs means trades occur directly on the blockchain, fostering a more transparent and permissionless financial ecosystem. While AMMs themselves don't directly handle fiat (AUD) or interact with AUSTRAC regulations in the same way as centralised exchanges, Australian users accessing these platforms typically fund their DeFi activities by first acquiring crypto on regulatory-compliant Australian exchanges and adhering to their own tax obligations regarding Capital Gains Tax (CGT) on profitable swaps or LP earnings.
Common questions
Q: What is "impermanent loss" and how does it relate to AMMs?
A: Impermanent loss is a common risk for liquidity providers in AMMs. It occurs when the price of the tokens you deposited into a liquidity pool changes relative to when you deposited them. If you were to withdraw your tokens, their dollar value might be less than if you had simply held them outside the pool. It's called "impermanent" because the loss only becomes permanent if you withdraw your assets; if the relative prices return to their original state, the impermanent loss disappears.
Q: Are AMM trades always cheaper than centralised exchange trades?
A: Not necessarily. While AMMs often have competitive trading fees, the overall cost can depend on several factors including network transaction fees (gas fees), the amount of liquidity in the specific pool, and the size of your trade. Larger trades on thinly capitalised pools can incur significant slippage, increasing the effective cost. Centralised exchanges might offer lower fees for highly liquid pairs or have incentives for high-volume traders, but may come with their own risks regarding centralisation.
Q: How do I find the best AMM to use for a particular token swap?
A: The "best" AMM depends on the specific tokens you want to swap, the blockchain they're on, and your priorities (e.g., lowest fees, least slippage, highest liquidity). Aggregators like 1inch or Matcha can be helpful as they scan various AMMs across different networks to find the most efficient routing for your trade. It's also wise to check the liquidity available for the trading pair on specific AMM platforms to minimise slippage for your transaction size.