Condition

After the swap, NostraSwap compares the market price between itself and other third-party DEXes. If the price difference is larger than $1.2\%$, then NostraSwap initiates arbitration and splits $10\%$of the profit to the trader, the rest goes to the liquidity providers.

These numbers are obtained by backtesting different combinations to maximize the liquidity providers' APY and ensure that every arbitration results in profit for the trader as well. See Backtesting.