Futures

Forward-price calculation under continuous compounding. A single building block — spot · er·t — useful for marking futures, computing fair forwards, or as an input to richer derivatives.

Contract: Futures.sol

Functions

Conventions

• spot — uint128, 18-decimal fixed-point (1e18 = 1.0).
• timeToExp — uint32, seconds to contract expiration.
• rate — uint64, annualized risk-free rate as 18-decimal fixed-point.
• Returns uint256 — futures price in 18-decimal fixed-point.
• The function is internal pure.

Quick example

import "defimath-lib/contracts/derivatives/Futures.sol";

uint256 fwd = DeFiMathFutures.futurePrice(spot, timeToExp, rate);

Important notes

• Continuous compounding. The model uses F = S · er·t. For dividend-paying assets, fold the dividend yield q into the rate as (r − q) at the call site.
• No strike — this is a forward, not an option. For option pricing, use the Options module; for cash-or-nothing digitals, use Binary options.
• Lowest gas in the library. ~400 gas total — typically cheaper than reading a single storage slot, so feel free to call it inline.

Limits & errors