Funding Risk

Context

Given Ethena Labs uses derivatives positions, such as perpetual contracts, to hedge the delta of the digital asset collateral, the protocol is exposed to "Funding Risk".

"Funding Risk" relates to the potential of persistently negative funding rates. Ethena is able to earn a yield from funding, but could also be required to pay funding.

While this is a direct risk to the protocol yield, we are comfortable in the data which is presented below, demonstrating negative yields do not persist and tend to revert to a positive mean.

Negative funding rates are a feature, rather than a bug of the system. USDe has been built with this in mind.

How Ethena manages Funding Risk

An Ethena insurance fund exists and will step in on occasions when the combined yield between the LST asset, such as stETH, and the funding rate for a short perpetual position, is negative. This ensures the collateral underpinning USDe is unaffected. Ethena does not pass on any "negative yield" to users who stake their USDe for sUSDe.

Positive Bias

ETH funding rates have exhibited natural positive bias and contango, with an average annualized rate of between 6% - 7.5% over the last 3 years on an open interest or volume-weighted basis, including the 2022 bear market.

Below we have charted the 30d moving average of funding rates and that positive bias is evident, particularly in 2021 and 2023.

Charting the distribution of funding rates per contract we can further see the positive bias per exchange, with the coloured box per contract indicating the middle 50% of datapoints. That middle 50% of funding data is predominantly positive values on most exchanges.

Margin of Safety

Using LST collateral, such as stETH, as collateral for USDe, provides an additional margin of safety in the form of the 4-5% annualized yield earned on stETH.

That is to say, protocol yield will only be negative when the combined stETH yield and funding rate sum to be negative.

Combining annualized stETH yields and funding rate values, we observe only 10.8% of days had a sum negative yield. That compares positively when compared to the ~20.5% of days yielding a negative funding rate when not also incorporating the stETH yield.

There has only been one quarter in the last 3 years where the average sum yield was negative and this data was polluted by the ETH PoW arbitrage period which was a one-off event that dragged funding deeply negative.

Mean-reversion

Funding rates have displayed mean-reverting characteristics, which is to say they may dip negative but those rates do not persist and don't drift lower over time. Positive baseline funding on some of the biggest derivative exchanges, with over 50% of open interest (Binance & Bybit), help keep funding rates naturally positive.

Reversion to a positive mean can be seen in the longest consecutive days of either positive or negative funding rates. Negative funding rates revert quicker thanks to the dynamics described above, with the longest streak of consecutive days with negative funding lasting just 13 days.

The longest streak of positive funding days has been 108 days, set in 2023 and charted below

For a more detailed explanation on the distribution of funding rates as it relates to USDe, please read this Twitter thread from our founder on the topic.