> For the complete documentation index, see [llms.txt](https://book.runesterminal.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.runesterminal.io/3.-runes/what-are-bitcoin-runes-for/defi.md).

# DeFi

Bitcoin runes also open up the possibility of [DeFi](https://chain.link/education/defi#:~:text=DeFi%20Definition,%2C%20smart%20contracts%2C%20and%20oracles.) on the Bitcoin network. Their [fungibility](https://en.wikipedia.org/wiki/Fungibility) means they are easy to split into pieces and put back together again. 

Since Runes are compatible with both the Bitcoin mainnet and Lightning network, they can be integrated into borrowing and lending platforms. 

This could mark the beginning of a new era for the Bitcoin network. While Bitcoin fungible tokens (and therefore DeFi) were possible previously, the cheaper and more efficient Runes protocol will allow for more innovative and user-friendly DeFi solutions on Bitcoin.<br>