Why is the cost of sale not showing in my sale by product summary

Hi there, gbanna!

Welcome to the Community! I'll help you to correct your Cost of Sales amount.

Adding to the product information works for future transactions. Basically, when you add a stock (inventory) item, QuickBooks will create a Stock starting value transaction in the background containing the initial cost (cost of sale / also accumulates the stock asset value). If didn't put a cost upon setup, you won't incur any cost of sale when you sell the item. To resolve this, we can edit and add the cost in the Stock starting value transaction of the item.

1. Click on the Gear icon.
2. Choose Products and services.
3. Click the down arrow beside Edit on the item in concern.
4. Choose Run report.
5. Set the Report period to All dates.
6. Find the first transaction that says Stock starting value and click to open it.
7. Update the Initial cost and click Save and close. 

Just to share, when you pull up a valuation report, the Asset Value of the item will also be 0.00 if you don't put a cost during setup. Therefore, the steps above will actually correct many reports that show the asset value.

You can also check about customising reports so you'll be guided on how the filter the data you only need.

I'm just a comment away if you have other concerns with your report. Take care and have a good one!