Short answer
Market value is the current estimated sale value of listed holdings.
Cost base is the record of purchase costs and adjustments.
Both are useful, but they answer different questions.
Practical overview
You want to know what your portfolio is worth now without losing the history of what you paid.
Ask yourself
Am I looking at current value, original cost, or unrealised gain?
Watch out for
Market value helps with net worth, but cost base explains performance, tax records, and the source of growth.
Try this
Pick one holding and line up units held, current price, current value, purchase records, and cost base notes.
Market value answers where you are now
Portfolio value is usually based on current market prices multiplied by the number of units or shares held. It helps show current exposure and total wealth.
Because prices move, this number can change without any buying or selling.
Cost base explains how you got there
Cost base records what was paid for investments, along with relevant costs and adjustments. It is part history, part tax evidence, and part performance context.
Without cost records, it is harder to understand whether portfolio growth came from contributions, reinvestment, or market movement.
Do not mix the two
A portfolio can have a high market value and a much lower cost base. That gap may represent unrealised gains, but it is not cash until assets are sold.
Showing both helps make the portfolio understandable without treating unrealised gains as spendable money.
Common questions
Is cost base the same as purchase price?
Not always. Cost base can include brokerage, adjustments, reinvestments, and other details depending on the asset and record-keeping rules.
Which number belongs in net worth?
Current market value is usually used for the asset value in net worth. Cost base supports history and tax records.
Should old trades still be kept?
Yes. Trade confirmations and statements help explain the cost base and ownership history.
A calmer way to keep the picture together
WealthScout is being built to connect assets, liabilities, records, and net worth in one private view. These guides explain the thinking behind it.
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