> For the complete documentation index, see [llms.txt](https://holdr.gitbook.io/holdr-protocol-overview/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://holdr.gitbook.io/holdr-protocol-overview/product/overview.md). # Overview Pools contain two or more tokens that traders can swap between. Liquidity Providers put their tokens in the pools in order to collect swap fees. Holdr adopts powerful features to slash gas costs, super-charge capital efficiency, unlock arbitrage with zero-token starting capital, and open the door to custom AMMs. ## Index Funds: Revolutionized Pools with high token-counts are like index funds, allowing users to have access to broad exposure to a variety of tokens. Where Holdr differs from the traditional notion of an index fund, however, is in the fees. **Instead of paying fees** to have a broker rebalance the pool, the **pools collect fees** as they're continuously rebalanced by traders making swaps. Furthermore, high token-count pools have the advantage of having many token pairs, creating additional opportunities to collect trading fees. Holdr's WeightedPools are based on an [N-dimensional invariant surface](https://balancer.finance/whitepaper/), a generalization of the constant product formula described by Vitalik Buterin. ## Serving Everyone With this mechanism, needs of both Liquidity Providers and Traders are served: * Liquidity Providers collect trading fees, while the their portfolio is continuously rebalanced * Traders gain access to an open, decentralized exchange that never closes, allowing them to swap what and when they like for low fees. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://holdr.gitbook.io/holdr-protocol-overview/product/overview.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.