Project Introduction

The Notional fixed-rate lending protocol, utilizing a novel on-chain automated market maker (AMM), enables DeFi, CeFi, and institutional traders to lend and borrow at fixed rates on the Ethereum network. Contributions include: the concept of fCash, term maturities, portfolios, and cash settlement.

fCash

fCash is a tokenized representation of an fCash flow. It represents the number of tokens (e.g., Dai) that an account has the right to receive (CASH_RECEIVER) or is obligated to pay (CASH_PAYER) upon its specified maturity date. For example, if an account holds +100 fCash tokens maturing at timestamp 100, it has the right to receive 100 Dai at any time greater than or equal to timestamp 100. Conversely, -100 fCash tokens of the same term mean the account is obligated to pay 100 Dai at timestamp 100. The lending mechanism will be detailed further below.

fCash for a given maturity (i.e., maturing at timestamp 100) can be swapped with other fCash tokens of the same maturity. However, it cannot be directly exchanged with fCash of different terms. Its also important to note that the right to receive fCash (CASH_RECEIVER) is freely transferable, whereas the obligation to pay (CASH_PAYER) is not.

Lastly, fCash tokens are not strictly ERC20 tokens because fCash tokens of different terms cannot be fungibly merged. fCash tokens can be represented under the ERC1155 token standard, which allows for interoperability.