Predicting the value of a stream at a specific point in the future to provide a "floor price"

[PaulRBerg]

Idea

Yet another productive call with NFTFI today - we dived deep into the difficulties of accepting stream NFTs as collateral.

One idea that sprung up was to provide NFTFI with an on-chain helper for calculating the guaranteed minimum value that a stream will have at a particular date or range in the future. This, in turn, will create a sort of "floor price" for the NFT.

The context is offer bidding. On NFTFI, lenders post bids with a maximum expiration date of 7 days. The issue is that during the bidding window, the recipient may withdraw, and so the collateral value of the stream may end up lower than what had originally been estimated.

To mitigate this risk, the lender could floor the value of the collateral to the amount that will remain due to be streamed at a future point in time. In other words, the lender would assume the worst-case scenario whereby all streamed assets are withdrawn at the time when the bid is accepted.

Note: this would only work for non-cancelable streams.

Implementation

• New periphery contract with helpers functions (we should think about what other helpers would be valuable)
• The contract would have a remainingAmountOf function (or something along these lines) which would:
  • Take three parameters: sablier, streamId, and timestamp
  • Return the amount of tokens that are due to be streamed starting at the particular point in time provided by the user
• Move the streamedAmountOf calculations to a library in V2 Core so that V2 Periphery can reuse them

[PaulRBerg]

Closing due to inactivity, will reopen if the NFTs pick up steam.