Why Does My Form 1099-DA Show a Higher Gain?

A Form 1099-DA can show proceeds from a crypto sale without showing the cost of the asset you sold. That can make the form look like it reports a much larger gain than your records do. The right response is to reconcile the sale to its original acquisition and keep the evidence for your basis.

First, check what the form actually reports

Form 1099-DA is a broker information return for certain digital asset dispositions. Proceeds and taxable gain are different numbers. In the 2025 reporting year, brokers generally report gross proceeds, while basis reporting is more limited. A blank basis field does not mean the asset had a zero basis. The IRS guide to Form 1099-DA and the form instructions explain the reporting fields.

For example, you buy 1 ETH for $1,800, transfer it to another exchange, and sell it for $3,200. The selling exchange may report $3,200 of proceeds without knowing about the $1,800 purchase. The possible gain is not $3,200 simply because basis is blank. You still need to account for the purchase, fees, holding period, and any other relevant transactions.

Why the numbers can differ

• The asset came from another platform. The selling broker may not have the purchase history from the first exchange or a self-custody wallet.
• A transfer was not matched. Tax software may treat an outgoing wallet transaction and an incoming exchange transaction as unrelated events.
• Records are incomplete. A missing wallet, old exchange account, DeFi transaction, or corrected broker form can change the calculation.
• You are comparing different totals. Broker proceeds, software gain, and the total on Form 8949 answer different questions.

How to reconcile the form

1. Download the final Form 1099-DA and the broker’s transaction detail. Note any corrected form.
2. Export the acquisition, transfer, and sale history from every exchange and wallet involved.
3. Match each reported disposition to the asset’s acquisition lot. Document the date, amount, basis, fees, and transfer path.
4. Investigate transactions the software classified as sales or acquisitions when they may be transfers. Do not change broker proceeds just to force the totals to match.
5. Compare the reconciled result with the reporting on Form 8949 and Schedule D. Have your tax preparer review any adjustment to a broker-reported transaction.

The IRS instructions for Form 8949 explain how digital asset dispositions and basis are reported. Keep the broker form, exports, wallet records, and a clear calculation with your tax files.

If an IRS notice arrives

A CP2000 proposes a change when third-party information does not match a filed return. It is not a final determination. Read the notice, follow its deadline, and respond with the records that support your figures. See the IRS guidance on CP2000 notices.

When the records need reconstruction

One clean exchange account may be straightforward to reconcile. Multiple wallets, missing basis, DeFi activity, or a closed exchange can require a transaction-level review. Our crypto tax reconciliation service traces the records and documents unresolved gaps. You can book a free consultation or request a $500 crypto diagnostic to define the cleanup scope.

This article is general information, not individualized tax or legal advice. Tax treatment depends on the transactions and supporting records.