The app's collection value includes an estimate for bottles we have no market price for. Your CSV export lists only real prices, so adding up its market price column always lands lower than the app. Nothing is wrong with either figure — they are answering slightly different questions.
The main reason: the estimate is not in the file
Your collection value has two parts — the market prices we actually hold, plus your collection's average bottle price standing in for the bottles we don't. The export has no row to put that second part in, so it simply isn't there.
You can see both halves for yourself. Tap the ⋯ beside Market value on Home, then About market value. The figure it quotes as the total for your covered bottles is the part of your collection the export can account for; the rest is the estimate.
Home → Market value ⋯ → About market value
Four smaller reasons the numbers won't tie
What differs | Why |
Filters and search | An export gives you what is on screen. If a filter, a search or a quick filter is applied, the file is a subset — the app's total is always the whole collection. |
Past bottles | Removed bottles are never in the app's total, but you can export them. Do that and you get a file of values the total never counted. |
Purchase price currency | In the bottle-per-row export, Purchase Price is written exactly as you entered it, with a Currency column beside it. Summing that column mixes currencies. The app converts every bottle first. |
Rounding and conversion | Every price in the file is rounded to two decimals, and exchange rates are applied per bottle rather than once to a total. Across a large collection these leave a small gap. |
If you want a figure that does add up
Export with the grouping that gives one row per wine per storage rather than one row per bottle. That format carries an Average and a Total column for both market price and purchase price, already converted into your currency — so the columns sum cleanly. It still won't include the estimate for uncovered bottles, because no export does.
The export is a CSV, so any spreadsheet app will total a column for you.
Next steps
Understanding your total collection value — exactly how the app's figure is built.
How to export your collection — the two groupings and the columns each one carries.