Thank you, that would help me to log the slippage. What I currently need though is to analyze the slippage in the period when there were the weird values. That's why I was asking for the meaning of the price in Zorro event log. From Zorro manual it seems like it's the fill price but when I compare it with MetaTrader log the prices are different. So is it the last price Zorro received before the position had been filled?