Your Profit = (Value of Unit) - (Purchase Price)
In a trading period, a buyer can purchase between zero and the maximum number of units available to purchase. Buyers earn money by purchasing units at prices that are below their values. Profits are computed by subtracting each unit's purchase price from that unit's value. Therefore,
For example, suppose the value of the first unit is $10.00 and the value of the second unit is $8.00. Suppose you buy the first unit for $6.00 and the second unit for $7.50. You buy no other units during this trading period. Your profits are:
profit from 1st unit = $10.00 - $6.00 = $4.00
profit from 2nd unit = $8.00 - $7.50 = $0.50
total earnings for the period = $4.00 + $0.50 = $4.50
Note that buyers do not receive the value of a unit unless they purchase the unit. Also, buyers can make negative profits if they buy at a price higher than value. The computer will keep track of all trades and earnings.