(Legacy) How are funding rates calculated in GRVT? (note: this system is getting phased out in October 10, 2025)

Calculate average fill prices for a set notional amount on both the bid and ask sides.

Take the median of:

A weighted average from several external exchanges.

Computed every second:

The median of (Premium / Index_Price) over the past minute.

Updated every minute.

Limited to ±1% (configurable) to prevent extreme funding swings.

Cap_Rate = 0.01 (1%, configurable) - this is the max payment, in % of your position.

Tracks cumulative funding changes, starting at 0.

Updated every minute:

Funding accrues every minute but is only settled when you trade or withdraw funds. Each trade or withdrawal triggers settlement for all open positions, generating individual entries per position. Deposits do not initiate settlement. There is no fixed settlement interval, funding payments occur only upon user activity.​

If your position size was Last_Position_Size and the Funding Index is F, then:

Afterward, Funding_Index_Start is updated to the current Funding Index if you still have a position, or reset to 0 if you fully closed it.

A note on the sign convention for Funding Payments in the "Funding History" tab of the UI : a negative number in the "Funding Amount" column (e.g. like in the screenshot below) indicates that user is paying ( a reduction in user's USDT Balance), and a positive amount indicates that user is receiving payment ( an increase in user's USDT Balance).