Description

When a trade is partially closed, _unregisterTrade calls storageT.applyReferralClose to apply the referral close:

function _unregisterTrade(
    ITradingStorage.Trade memory _trade,
    int _percentProfit,
    uint _collateral,
    uint _feeAmountToken, // executor reward
    uint _lpFeeToken,
    uint _tier
) private returns (uint usdcSentToTrader) {
    //...
    (uint feeAfterRebate, uint referrerRebate) =
        storageT.applyReferralClose(
            _trade.trader,
            _lpFeeToken,
            _trade.initialPosToken.mul(_trade.leverage)
        );

However, the third parameter to applyReferralClose should be the size of the leveraged position that was closed, instead of the total leveraged position.

In applyReferralClose, the third parameter is only used in the emitted TradeReferred event.

Impact

The emitted TradeReferred event for a partial close will have an incorrect closed leveraged position size.

Recommendations

Make this _collateral.mul(_trade.leverage).

Remediation

This issue has been acknowledged by Avantis Labs, Inc., and a fix was implemented in commit f4ef1c84↗.