Your 1099-DA Shows Huge Gains But You Lost Money? Here's How to Fix It

In This Article

1. What the 1099-DA Actually Reports
2. Why Cost Basis Is Missing
3. The Dollar Impact of Filing with $0 Basis
4. Step-by-Step: How to Reconstruct Your Cost Basis
5. Cost Basis Methods: FIFO, LIFO, HIFO, and Specific ID
6. What Happens If You File with $0 Basis
7. Small Amounts Still Matter
8. When Professional Help Makes Sense vs. DIY
9. NJ State Treatment
10. Frequently Asked Questions

What the 1099-DA Actually Reports

Form 1099-DA, issued for the first time for Tax Year 2025, reports gross proceeds from digital asset dispositions in Box 1f. For TY2025, brokers report proceeds reduced by allocable transaction fees and commissions per Reg. Section 1.6045-1. This number represents what the exchange sent you (or the FMV of what you received in a swap) — not your profit.

Cost basis (Box 1g) is often blank or shows $0 for TY2025. The IRS 1099-DA instructions explicitly state that brokers are not required to report basis information for sales effected in 2025. Mandatory basis reporting begins for covered digital assets acquired on or after January 1, 2026. Some brokers may voluntarily report basis for assets acquired and sold on their platform, but most are not yet doing so.

According to the Coinbase/CoinTracker 2026 Crypto Tax Readiness Report (survey of 3,000 U.S. crypto users), 61% of respondents were unaware of the new 2025 tax rules, and 66% are approaching tax season without understanding the reporting requirements. The basis gap is the primary source of confusion — and overpayment.

When basis is missing, the 1099-DA makes it appear as though 100% of proceeds are taxable gain. A taxpayer who bought 1 ETH at $3,000 and sold it at $3,200 had a $200 gain. But if the 1099-DA shows $3,200 in proceeds and $0 in basis, it looks like a $3,200 gain — overstating the tax by approximately $900 at a 30% combined rate.

Why Cost Basis Is Missing

There are several technical reasons why exchanges cannot report your cost basis, and understanding them is essential to fixing the problem:

1. Transfers from external wallets. When crypto is transferred into an exchange from a personal wallet, hardware wallet, or another exchange, the receiving platform has no record of when or at what price the asset was originally purchased. The exchange sees an inbound transfer — not an acquisition. Boxes 12a and 12b on the 1099-DA flag transferred-in assets. If either is populated, the receiving platform likely does not have the original purchase price or date.

2. Transfers from other exchanges. Moving crypto from Coinbase to Kraken and then selling on Kraken creates the same problem. Kraken does not know the Coinbase purchase price. Under the pre-2025 system, there was no standardized mechanism for exchanges to share cost basis data on transfers. Rev. Proc. 2024-28 establishes per-wallet basis tracking going forward, but it does not retroactively solve the problem for assets acquired before 2025.

3. DeFi activity. On-chain swaps, liquidity pool deposits, staking rewards, airdrops, bridge transactions, and other DeFi activity occur entirely outside centralized exchange infrastructure. No exchange has visibility into these transactions. The DeFi broker reporting rule (T.D. 10021) was repealed by Congress via the Congressional Review Act (H.J.Res.25, signed April 10, 2025). Pure DeFi activity will not appear on any 1099-DA.

4. Pre-2025 acquisitions. Assets purchased before 2025 are "noncovered" — brokers are not required to track or report basis for them. Even if the asset was bought and sold on the same exchange, the broker may not report basis for noncovered lots.

5. Broker limitations. Even for assets acquired on-platform, some brokers have not built the infrastructure to track lot-level basis across forks, airdrops, staking events, and complex transaction types. Notice 2024-56 provides penalty relief for brokers making good-faith efforts to comply in TY2025, acknowledging the systems are still maturing.

The Dollar Impact of Filing with $0 Basis

The cost of accepting a $0 basis without correction can be substantial. Consider three hypothetical scenarios:

The third scenario is the worst: the taxpayer actually lost $1,000 but the 1099-DA makes it look like a $3,000 gain. Without correcting basis, the filer pays tax on phantom income AND loses the ability to use the capital loss to offset other gains.

For taxpayers with multiple transactions across multiple exchanges, the aggregate overpayment can reach thousands or tens of thousands of dollars. A portfolio with $50,000 in total proceeds and $45,000 in actual basis would show $50,000 in gains on the 1099-DA but only had $5,000 in actual gains — a $13,500 overpayment at a 30% rate.

Step-by-Step: How to Reconstruct Your Cost Basis

Correcting the $0 basis problem requires gathering records from all platforms and wallets where crypto was acquired, then applying a consistent cost basis method across all dispositions.

Step 1: Gather Records from Every Platform

Download transaction history CSVs from every exchange and platform where crypto was purchased, received, or earned. This includes:

• Centralized exchanges: Coinbase, Kraken, Gemini, Robinhood, Binance.US, Crypto.com
• Payment apps: PayPal, Venmo, Cash App (all support crypto purchases and issue 1099-DAs)
• DeFi wallets: Export from Etherscan, Solscan, or blockchain explorers using your wallet addresses
• Mining/staking platforms: Records of rewards received with dates and FMV at receipt
• Airdrop records: Date received, amount, FMV at receipt (basis under IRC Section 61)

Step 2: Map All Transfers Between Wallets

Transfers between wallets owned by the same person are NOT taxable events (IRS FAQ 81). However, they create the basis tracking gap. Map every transfer by:

• Matching withdrawal timestamps from the sending platform to deposit timestamps on the receiving platform
• Verifying amounts (accounting for network fees consumed during transfer)
• Carrying over the original cost basis and acquisition date to the receiving wallet

Rev. Proc. 2024-28 requires per-wallet basis tracking going forward. For TY2025, taxpayers must allocate basis to specific wallets and use the method elected (FIFO is the default if no election is made).

Step 3: Choose and Apply a Cost Basis Method

Four methods are available. The choice of method must be applied consistently per wallet under Rev. Proc. 2024-28:

• FIFO (First In, First Out): Default method. Oldest lots are sold first. Often results in lower basis (and higher gains) during bull markets because the oldest (cheapest) lots are disposed of first.
• LIFO (Last In, First Out): Newest lots sold first. Can result in higher basis in rising markets.
• HIFO (Highest In, First Out): Lots with the highest basis are sold first, minimizing current-year gains. Generally the most tax-efficient method.
• Specific Identification: The taxpayer identifies exactly which lot is being sold, providing maximum control over gain/loss recognition. Requires adequate records to identify each lot.

For most taxpayers, HIFO produces the lowest current-year tax liability because it assigns the highest-cost lots to each sale first, minimizing gains or maximizing losses.

Step 4: Report Correct Basis on Form 8949

Form 8949 is where the correction happens. Even if the 1099-DA shows $0 basis, the taxpayer reports the actual basis in Column (e) of Form 8949. The IRS instructions for Form 8949 explicitly allow taxpayers to report a different basis than what appears on the information return.

The "Applicable checkbox on Form 8949" field on the 1099-DA directs which box to use:

• Code Y: Most common for TY2025. The broker cannot determine short-term vs. long-term and is not reporting basis. Use your own records to determine holding period and enter in Box H (short-term) or Box K (long-term).
• Code H or K: Broker indicated holding period but did not report basis. Use the corresponding box and supply your own basis.
• Code G or J: Basis was reported to the IRS. Use the corresponding box and verify accuracy.

Step 5: Attach a Statement Explaining Discrepancies

When the basis reported on Form 8949 differs from the 1099-DA, attach a statement explaining why. Include: the exchange name, the 1099-DA box values, your actual basis with supporting documentation reference, and the method used (FIFO, HIFO, Specific ID). This preempts a CP2000 notice by showing the IRS that the discrepancy was intentional and documented.

What Happens If You File with $0 Basis

Two outcomes are common:

Outcome 1: Overpayment. The taxpayer accepts the 1099-DA at face value, reports $0 basis on Form 8949, and pays tax on the full proceeds as gain. The IRS accepts this — it is more tax than actually owed. The taxpayer overpays, potentially by thousands of dollars, with no correction unless an amended return is filed within 3 years under IRC Section 6511.

Outcome 2: CP2000 notice. The taxpayer reports a different number than the 1099-DA without adequate documentation. The IRS Automated Underreporter (AUR) system flags the mismatch and generates a CP2000 notice — a proposed adjustment adding tax on the "missing" income, plus interest and potential accuracy-related penalties under IRC Section 6662. The taxpayer then has 30 days to respond with documentation supporting the correct basis. Over 4 million CP2000 notices are issued annually.

The worst outcome is filing with incorrect basis and no documentation. The second-worst outcome is overpaying by filing with $0. The correct outcome is reconstructing actual basis and reporting it on Form 8949 with supporting documentation.

Small Amounts Still Matter

Under IRS FAQ 108, all digital asset transactions must be reported "regardless of the amount." There is no de minimis threshold. A $50 crypto sale triggers Form 8949 reporting. A swap between two tokens — even a $10 stablecoin swap — is a taxable event if the tokens are materially different in kind or extent.

A transfer between wallets owned by the same person is NOT a taxable event (FAQ 81), but it may appear on the 1099-DA if the exchange treats the outbound transfer as a disposition. Verify each line on the 1099-DA against your actual transactions — some reported "dispositions" may be non-taxable transfers that need to be excluded from Form 8949.

Congressional proposals for a de minimis threshold (including a $300 per-transaction threshold with $5,000 annual cap) have been introduced but not enacted as of April 2026.

When Professional Help Makes Sense vs. DIY

Crypto tax software (Koinly, CoinTracker, CoinLedger) can automate much of the reconciliation process by importing transaction histories from exchanges and wallets, matching transfers, and applying cost basis methods. For taxpayers with activity on a single exchange and no transfers, software alone is usually sufficient.

Professional reconciliation becomes valuable when:

• Multiple exchanges were used — basis must be tracked across platforms with no automated transfer matching
• DeFi activity occurred — on-chain swaps, LP deposits/withdrawals, staking, and bridge transactions require manual classification
• Transfers between wallets exist — matching sends and receives across chains with different confirmation times and fee structures
• The 1099-DA shows significant discrepancies — large gaps between reported and actual basis suggest complex transaction histories
• Prior years were not filed correctly — amended returns for 2021-2024 may be needed to establish correct carryover basis

For the exchange-by-exchange breakdown of what each platform reports on the 1099-DA, see Form 1099-DA by Exchange. For the 1099-DA Reconciliation Service, a CPA reviews every line, reconstructs basis, and files Form 8949 with supporting documentation.

NJ State Treatment

New Jersey fully conforms to federal crypto treatment. Digital asset gains are taxed as NJ gross income under N.J.S.A. 54A:5-1(c) (net gains from disposition of property) with no state-level exclusion, preferential rate, or separate reporting requirement.

NJ taxes capital gains as ordinary income at rates from 1.4% to 10.75%. There is no NJ equivalent of the federal long-term capital gains rate. A crypto gain taxed at 15% federally (long-term) is taxed at the taxpayer's full marginal rate for NJ purposes.

The $0 basis problem is equally damaging on the NJ return. Overstating gains on the federal return flows directly through to NJ because NJ uses the same gain calculations. Correcting basis on Form 8949 corrects both the federal and NJ returns simultaneously.

Related reading: The 1099-DA $0 Basis Trap | Form 1099-DA by Exchange | 1099-DA Reconciliation Service | Crypto Tax Services

## Frequently Asked Questions

Why does my 1099-DA show $0 cost basis?

For TY2025, brokers are not required to report cost basis. The IRS instructions explicitly allow brokers to leave Box 1g blank. $0 basis is common for transferred-in assets, DeFi activity, and pre-2025 acquisitions where the exchange does not have purchase records.

Can I report a different basis than what's on my 1099-DA?

Yes. The IRS Form 8949 instructions explicitly allow taxpayers to report actual cost basis even when it differs from the information return. Report the correct basis in Column (e) and attach a statement explaining the discrepancy.

What cost basis method should I use for crypto?

Four methods are available: FIFO (default), LIFO, HIFO, and Specific Identification. HIFO generally produces the lowest current-year tax because it assigns the highest-cost lots to each sale first. Under Rev. Proc. 2024-28, the method must be applied consistently per wallet.

What happens if I just file with $0 basis?

The IRS will accept the return — but you will overpay, potentially by thousands of dollars. Alternatively, if you report a different number without documentation, the IRS may issue a CP2000 notice proposing additional tax based on the 1099-DA figures.

How many crypto users are affected by missing basis?

According to the Coinbase/CoinTracker 2026 Crypto Tax Readiness Report, 61% of U.S. crypto holders surveyed were unaware of the new 2025 tax rules, and 66% are approaching tax season without understanding the reporting requirements. The basis gap affects anyone who transferred crypto between platforms or used DeFi.

Does NJ tax crypto differently than the federal government?

NJ taxes crypto gains as ordinary income at rates up to 10.75% — there is no preferential capital gains rate at the state level. NJ fully conforms to federal crypto treatment, so correcting basis on Form 8949 corrects both the federal and NJ returns.

Do I need to report small crypto transactions?

Yes. Under IRS FAQ 108, all digital asset transactions must be reported regardless of the amount. There is no de minimis threshold. A $50 sale, a $10 swap, and a staking reward of any size all trigger reporting requirements.

How long do I have to amend a return if I overpaid?

Under IRC Section 6511, amended returns must be filed within 3 years of the original filing date (or 2 years from the date tax was paid, whichever is later). If you filed TY2025 with $0 basis and overpaid, you have until approximately April 2029 to file an amended return claiming a refund.