SCCP-56: Reduce exchange fees of sETH and sBTC to 0.3%

Simple Summary

Reduce exchange fees of trades into sETH, iETH, sBTC and iBTC to 0.3% to align with all other non-crypto synths.

Abstract

As ETHUSD and BTCUSD price networks are now based on 0.5% deviations, lower the exchange fees into those synths to the base 0.3% fee that is used elsewhere.

Motivation

Other synths in the Synthetix protocol - forex, commodities, equities and indexes - are all based on 0.5% deviations on their respective Chainlink networks yet all use 0.3% exchange fees. The BTCUSD network has recently been lowered to use a 0.5% deviation to be in line with ETHUSD, so it seems timely to a) reduce the fees on sBTC and iBTC to match sETH and iETH and b) reduce them both to 0.3% to line up with the rest of the non-crypto synths using 0.5% deviations.

Copyright

Copyright and related rights waived via CC0.