How Mezzi Calculates Realized and Unrealized Gains

Last updated: August 21, 2026

Overview

An unrealized gain is the current market value of a position you still hold minus its cost basis — profit on paper, not yet taxable. A realized gain or loss comes from positions you've sold, calculated from the sale proceeds against the cost basis of what was sold. Mezzi derives both from the cost basis and transaction history your institution sends through the connection, so the figures are only as complete as the history that arrives.

📌 What You Need to Know

Unrealized gains

For every holding you still own, Mezzi compares the position's current market value against its cost basis:

Unrealized gain = market value − cost basis

Market value comes from the current price of the security multiplied by the quantity your institution reports. Cost basis comes from your institution. Neither is calculated by Mezzi from scratch, which is why an unrealized figure can be missing or odd when either input is missing — most commonly for holdings without a public ticker, where there's no price to mark against.

Realized gains

A realized gain or loss appears when a position is sold. Mezzi matches the sale against the cost basis of the shares disposed of and records the difference.

This depends entirely on the transaction history your institution transmits. If a sale predates the window of history your institution shares, or if the transaction never came through, the corresponding realized gain won't appear. See Why Are Some of My Transactions Missing?.

These are not tax documents

Mezzi's gain figures are for understanding your portfolio, not for filing. They don't apply wash-sale adjustments, they don't distinguish short-term from long-term treatment for tax purposes, and they don't replace the 1099-B your brokerage issues. Use Mezzi to see where you stand and to plan; use your broker's tax forms to file.

Crypto is a known weak spot

Realized gain and loss figures on crypto exchange connections can be inaccurate, because exchanges transmit transfers, conversions and trades inconsistently. This is documented separately — see Why is my Coinbase realized gain/loss inaccurate in the help center before assuming a crypto figure is wrong on Mezzi's side.

Important Notes

Gains are not the same as performance. A return percentage measures how your capital performed over a period and should exclude money you moved in or out. A gain measures value against what you paid. The two answer different questions and will not agree — see Why Do Performance Numbers Differ From My Brokerage?.

Holdings without a ticker distort both. If a position can't be priced, its market value can't be marked and its unrealized gain is unreliable. Employer retirement plan funds are the usual case: Why Your Retirement Plan Holdings Show as "Unknown" or Have No Ticker.

Manually added assets behave differently. Real estate, vehicles and other alternatives you enter yourself are modelled as a straight line from purchase price to current value, so their "gain" is simply the difference between the two values you supplied. There is no daily mark.

🗨 Still Need Help?

If a gain figure looks wrong, email help@mezzi.com or text/call (415) 763-6997 with the account name, the holding, the figure Mezzi shows, and the figure your brokerage shows.

Common Questions

  • Why is my unrealized gain missing for one holding? Usually because cost basis didn't come through for that position, or because the security has no public price to mark against. Send us the account and holding name and we'll check what your institution is returning.

  • Does Mezzi track short-term versus long-term gains? Not as tax treatment. Mezzi shows gains against cost basis; the holding-period classification that matters for your return comes from your brokerage's tax reporting.

  • Will Mezzi show a realized gain for a sale from years ago? Only if that transaction is within the history your institution shares. Older activity generally isn't available — see How Cost Basis and Tax Lots Are Tracked.

  • Do dividends count as realized gains? No. Dividends are income, not a disposal, and appear in Mezzi's income and dividend figures rather than in realized gains.