> ## Documentation Index
> Fetch the complete documentation index at: https://help.arcus.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# How are funding rates calculated?

**Regular Trading Hours:** The perpetual funding rate is calculated from two components:

* the premium component (perpetual contract vs. underlying)
* added to a base component (fixed at SOFR + 0.5%)

During regular hours, the premium is sampled continuously by comparing the price of the perpetual contract vs. the price of the underlying asset.

**Outside Regular Trading Hours:** The rate snaps to the fixed financing rate (SOFR + 0.5%) and the basis component is dropped:

* so positions held overnight or over a weekend don't face shifting funding.

**Corporate actions:** these trigger separate automatic adjustments when the oracle reflects the event, keeping the perp aligned with the underlying's total return.