What happens to your break-even when you buy more

Most people build a holding over time: some shares now, some more later, at a different price. Each buy changes two numbers: your average cost and your break-even.

One holding, two buys

Say you bought 125 MTN Ghana shares at GHS 6.50. With fees, that cost GHS 830.78, and the break-even was GHS 6.80.

Later the price is GHS 7.20 and you buy 100 more. That trade is worth GHS 720.00, falls in the 2.25% tier, and costs GHS 736.20 with GHS 16.20 in charges.

Your new average cost

Add up everything you've paid and divide by the shares you hold:

GHS 1,566.98 ÷ 225 = GHS 6.9644 a share, fees included.

Your new break-even

Selling all 225 shares has its own fees, so the break-even sits above the average cost. The lowest price at which the sale gets back GHS 1,566.98 is GHS 7.13.

So the second buy moved the break-even from GHS 6.80 to GHS 7.13. Buying at a higher price raises it; buying lower would bring it down.

Selling part of a holding

If you later sell some shares, Breakeven takes cost out in proportion (the average-cost method), so the average cost of what you still hold doesn't change. It does recalculate the break-even for the shares that are left, because a smaller sale can fall in a different fee tier.