The calculation of illegal income in insider trading cases is a cross problem between finance and law.In the case of insider trading,if all the stocks involved have been cleared,the illegal income is determined by the actual profit,and the illegal profit of the uncleared stocks can be calculated as the book profit.When calculating book profit,the closing price of the stock on the base date is the basis of valuation.In the case of the realization of good news,if the stock has a rise or fall limit after the resumption of trading,the trading day that opens the rise or fall limit after the resumption of trading should be taken as the base day for calculation;If there is no rise or fall limit,the trading resumption date is the base date for calculation.The cost of unliquidated shares is determined using the average purchase price method.Stock dividends during insider trading should also be counted as illegal gains.