> For the complete documentation index, see [llms.txt](https://docs.infinitypools.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.infinitypools.finance/protocol-overview/tradfi-analogy/loan-and-option-styles.md).

# Loan & option styles

InfinityPools has three instruments that can all be exercised differently:

1. Fixed term loan - this instrument is similar to a European synthetic option as it cannot be exercised before it matures (that said, same as a European synthetic option, you can still lock in profits at any point).
2. Revolving loan - this instrument most resembles an American synthetic option but is more powerful as traders can get a refund on "unspent" premium. In other words, if a trader pays a premium for an hour long trade but decides to exercise after 30 minutes, they will get back 50% of their paid premium.
3. Periodic loan - this instrument is a combination of the previous two, and is the main InfinityPools trade mechanism. Periodic loans start as fixed term loans and switch over to revolving loans after a preset lock in period.