PolyTax — Tax Report Exporter

Polymarket gives you zero tools to export your trades. PolyTax fixes that.

You closed a position. Maybe you made money, maybe you didn't. Either way, tax season is coming and you need records. You open your Polymarket portfolio and realize there is no export button. No CSV. No transaction history download. Nothing. You are left scrolling through closed positions one by one, copying numbers into a spreadsheet by hand, hoping you don't miss a trade or get a decimal wrong.

That is the problem PolyTax was built to solve.

WHY POLYMARKET TAX REPORTING IS SO HARD

Prediction markets are taxable events in the United States. The IRS treats prediction market gains the same way it treats short-term capital gains. Every closed position needs to be reported with a cost basis and realized profit or loss.

But Polymarket gives you nothing to work with:

• No built-in export or download feature for closed positions
• No transaction history CSV or PDF
• No cost basis tracking across multiple entries in the same market
• No way to separate wins from losses at a glance
• No structured data format you can hand to your accountant or tax software

Most traders end up doing one of two things. They ignore it entirely and hope nobody notices. Or they spend hours manually reconstructing their trade history from memory and on-screen data. Both options are bad.

PolyTax eliminates this problem entirely.

WHAT THIS EXTENSION DOES

PolyTax is a Chrome extension that adds an "Export Tax Report" button directly to your Polymarket portfolio page. One click and it pulls your closed positions from the Polymarket data API, formats everything into a clean CSV file, and downloads it to your computer. No spreadsheets. No manual entry. No copy-pasting.

Here is what you get:

One-Click CSV Export -- Go to your portfolio page, click the blue "Export Tax Report" button, and your file downloads instantly. The entire process takes under three seconds.

Structured Tax Data -- Every row in the CSV includes the date the position closed, the market title, the outcome you held, your total cost basis in dollars, and your net realized PnL. These are the exact fields your accountant or tax software needs.

Automatic Sorting -- Positions are sorted by date with the most recent trades first. No need to reorganize anything after export.

Cost Basis Tracking -- The cost basis column reflects your total investment in each position, pulled directly from the Polymarket data API. No manual calculation required.

PnL Breakdown -- See exactly how much you gained or lost on every single trade. Positive numbers are gains. Negative numbers are losses. Clean and unambiguous.

HOW IT WORKS

1. Install PolyTax from the Chrome Web Store.
2. Go to polymarket.com and log in to your account.
3. Navigate to your Portfolio page.
4. Click the blue "Export Tax Report" button that appears on the page.
5. Your CSV file downloads automatically.

That is it. No configuration. No setup. No account creation. You click one button and your tax data is ready.

WHY IT LIVES ON THE PAGE

Most Chrome extensions use a popup window for their main interface. PolyTax does not. The export button is injected directly into your Polymarket portfolio page using Shadow DOM isolation. This means it feels like a native part of the site rather than a bolt-on tool floating in a corner.

The button only appears on the portfolio page. It does not show up on market pages, the homepage, or anywhere else. It stays out of your way until you need it.

DEMO MODE

Not sure if the extension works the way you need it to? PolyTax includes a built-in Demo Export button. Click it on any portfolio page and it generates a sample CSV with realistic prediction market data -- covering crypto, politics, sports, and economic markets. You can open the file, inspect the format, and confirm it matches what your tax software or accountant expects before using it with real data.

REAL SCENARIOS WHERE THIS HELPS

Tax season preparation: You traded on Polymarket throughout the year. You have 25 closed positions across politics, crypto, and sports markets. Instead of scrolling through each one and typing numbers into a spreadsheet, you click Export Tax Report and hand the CSV directly to your CPA.

Accountant handoff: Your accountant asks for a breakdown of all prediction market activity. You send them a single CSV file with dates, market names, cost basis, and PnL. They can import it directly into their tax preparation software without any back-and-forth.

Portfolio review: You want to understand your overall performance. The CSV shows every closed position sorted by date. You open it in Google Sheets, add a SUM formula on the PnL column, and instantly see your total realized gain or loss for the year.

Loss harvesting analysis: You need to identify losing positions to offset gains from other investments. The PnL column clearly shows negative values for every trade that lost money. Filter the column for negative numbers and you have your loss report.

Record keeping: Even if you are not filing taxes right now, you want a permanent record of your trading activity. Export the CSV at the end of each month and store it. If Polymarket ever changes its interface or data access, you already have your records saved locally.

Multiple market tracking: You traded in both political and crypto markets. The CSV includes the full market title for each position, so you can sort or filter by market type. No need to remember which trades were which.

WHAT THIS EXTENSION DOES NOT DO

• It does not access your Polymarket account credentials or private keys
• It does not execute trades or modify your portfolio in any way
• It does not send your data to any external server or third party
• It does not track your browsing activity outside of polymarket.com

The only permissions it uses:

• storage -- Saves your extension preferences locally in your browser
• Host access to data-api.polymarket.com -- Reads your closed position data from the public Polymarket data API. This is the same API the Polymarket website itself uses to display your portfolio.

All data processing happens entirely in your browser. The CSV file is generated locally and saved directly to your computer. Nothing leaves your machine.

FREE TO USE

PolyTax exports up to 30 closed positions per download at no cost. No account required. No sign-up. No payment.

For most traders, 30 positions covers an entire year of activity. The export includes your most recent 30 closed positions sorted by date.

THE DATA BEHIND YOUR EXPORT

Every row in the CSV maps directly to a closed position from the Polymarket data API:

Date -- The timestamp when the position was resolved Market -- The full title of the prediction market Outcome -- The outcome you held (Yes, No, or a named option) Cost Basis ($) -- Your total dollar amount invested in that position Net PnL ($) -- Your realized profit or loss after resolution

No rounding tricks. No hidden adjustments. The numbers come straight from the same data source that powers your portfolio page on Polymarket.

WHO THIS IS FOR

• US-based Polymarket traders who need to report prediction market gains and losses on their tax returns
• Active traders with multiple closed positions who do not want to track everything manually
• Anyone working with an accountant or CPA who needs structured trade data in a standard format
• Traders who want a permanent local record of their Polymarket activity
• Casual users who just want to see a clean summary of what they gained or lost

GETTING STARTED

Install PolyTax, go to your Polymarket portfolio, and click Export Tax Report. Your CSV downloads in under three seconds.

No account needed. No sign-up. No credit card. Just one click and your tax data is ready.