Average cost per share
Total spent divided by shares owned.
Your average cost per share is the total amount you have invested in something divided by the number of shares you own.
How to use it
It tells you, at a glance, whether you are ahead: if the current price is above your average cost, your position is in profit.
Dollar-cost averaging tends to keep your average cost below the average price over the same period, because you buy more shares when prices are low.
ExampleBuy 10 shares at $50 and 10 at $70: you spent $1,200 for 20 shares, an average cost of $60.