1. Have Not Decided Yet
2. Funds received through purchase of vouchers
3. Transaction Fee

1. Bitcoins
2. Gold
3. Contracts

Open-Transactions supports a range of financial instruments, such as cheques, vouchers, and untraceable digital cash. These are all analogous to the same financial instruments that we all use at normal banks today. Everyone already has an intuitive understanding of these financial instruments, because we use them regularly in our normal daily lives.

Open-Transactions allows users to issue and manipulate digital assets. Users may create many pseudonyms (public keys), each of which may own asset accounts of various types. Users can transfer digital assets securely between accounts (even a server cannot change balances or forge transactions.) Users can also operate “cash-only” (without accounts) for maximum anonymity.

Open-Transactions also implements higher-level, contract-based transactions such as payment plans and markets with trades. The markets on Open-Transactions support market orders, limit orders, fill-or-kill orders, day orders, stop orders, and stop limits, just like trading on a real market. OT also supports basket currencies.
All of this is accomplished in such a way that all parties are able to prove, at all times, which transactions have cleared and which instruments are authorized, without having to store their entire transaction history, but instead by merely keeping the last signed receipt.

Without the special mechanism that makes this possible, all parties would otherwise be forced to store all receipts forever, just to prove their story in the event of a dispute. (Any system where parties cannot “prove their story” will eventually break down and fail.) Thankfully, this is not a problem in Open-Transactions, which proves everything using only the last signed receipt.