> For the complete documentation index, see [llms.txt](https://docs.reya.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.reya.xyz/chain/introduction.md).

# Introduction

ReyaChain is the next iteration of Reya - designed to provide millisecond-level trading speed, whilst inhereting Ethereum's security. We achieve this by being the first ever trading-specific based rollup. You can find the technical details here: <https://x.com/0xSimonJones/status/1944737748381839671>

Today, Reya uses a forked and heavily customised version of Arbitrum Orbit. The infrastructure upgrade - as Reya transitions from an optimistic rollup to a based rollup - will happen in stages without any impact to trading.