How Polymarket Works - What CRA Sees on the Blockchain
Polymarket is a decentralised prediction market platform where you buy binary outcome shares settled in USDC on the Polygon blockchain. When a market resolves, winning shares redeem at $1 USD each and losing shares expire worthless. You can also trade shares before settlement at the prevailing market price.
USDC is treated as a capital property under CRA's interpretation of cryptocurrency, consistent with the CRA's position on digital assets generally. Polymarket does not issue T5008 or T5 slips. No tax forms are provided. Your proxy wallet address - a smart contract address distinct from your sign-in wallet - is the starting point for calculating your Canadian tax position.
How Canada Likely Taxes Polymarket Profits
CRA has not issued specific guidance on prediction markets. Three possible treatments apply depending on the nature and frequency of your activity:
Income from business - if systematic
If CRA applies the "badges of trade" test and finds systematic, profit-motivated trading with a business-like approach, 100% of net profits are taxable at your marginal federal and provincial rates (up to 33% federally). The badges of trade test considers: frequency of transactions, profit motivation, connection to an existing trade, whether the asset was bought for resale, and the amount of time devoted to the activity.
Capital gains - if speculative but not a business
If your activity is occasional or speculative rather than organized and systematic, CRA is more likely to treat gains as capital in nature. Under current law, 50% of net capital gains are included in income (the taxable capital gain). This is reported on Schedule 3 of your T1 return. Note: the proposed increase to a 2/3 inclusion rate for gains over $250,000 was announced in the 2024 federal budget but was subsequently cancelled - the 50% rate continues to apply.
Recreational gambling - potentially not taxable
CRA generally does not tax occasional gambling winnings for individuals. If your Polymarket activity more closely resembles casual betting than systematic trading, profits may be tax-free. However, if the activity constitutes a business, gambling income becomes taxable. The line between casual gambling and a business is not always clear, and no CRA ruling on prediction markets exists.
The USDC Layer - ACB Calculations on Top
Under CRA rules, USDC is a capital property. The ACB (Adjusted Cost Base) method tracks your average cost across all USDC acquisitions. When you sell or dispose of USDC (for example, converting back to CAD), you realize a capital gain or loss equal to: proceeds minus ACB minus reasonable selling expenses.
- Buying USDC: increases your ACB pool, averaged across all USDC holdings
- Depositing to Polymarket: transfer to your own proxy wallet - not a disposition (same beneficial owner)
- Withdrawing USDC: receiving USDC back to your personal wallet - not a disposition
- Converting USDC to CAD: capital disposition - gain or loss equals proceeds minus ACB per unit
The superficial loss rule may also apply: if you sell a Polymarket position at a loss and then repurchase the same position within 30 days, the loss could be denied and added to the ACB of the reacquired position. The application of this rule to prediction market contracts - which are unique per event - is unclear, but caution is warranted.
What DYOR.tax Calculates for Canadian Traders
- Proxy wallet scan covering all trades, settlements, and redemptions
- Prediction market P&L with activity pattern assessed against CRA classification factors
- USDC disposals calculated under ACB method with running pool balance
- 50% capital gains inclusion applied to reportable gains
- Superficial loss flag on position repurchases within 30 days
- Optional History CSV enrichment for deposits and withdrawals
Canadian Filing Requirements for Polymarket
- Capital gains: Schedule 3 (Capital Gains and Losses) on your T1 return
- Business income: T2125 (Statement of Business or Professional Activities)
- Gambling winnings (if non-taxable): no specific form needed, but document your position and rationale
- Filing deadline: April 30 for most individuals; June 15 for self-employed individuals (but any balance owing is still due April 30)
- Record keeping: keep all records for at least 6 years from the end of the tax year (CRA standard audit window)
Common Polymarket Tax Mistakes in Canada
- Treating capital gains as 100% taxable: Only 50% of capital gains are included in income under the current inclusion rate. Overstating your taxable gain is a common error.
- Ignoring ACB calculations on USDC: Every USDC conversion back to CAD is a capital disposition. The gain may be small if USDC held its peg, but it still needs to be calculated and reported.
- Assuming gambling exemption applies without analysis: CRA may disagree if the activity was systematic. Document your trading frequency, intent, and approach before concluding the activity is non-taxable gambling.
- Not tracking the superficial loss rule: Repurchasing the same Polymarket position within 30 days of realizing a loss may deny the loss. This is easy to miss without proper tracking.
- Filing on the wrong form: Capital gains go on Schedule 3; business income goes on T2125. Filing capital gains as business income (or vice versa) can result in over- or under-taxation and CRA queries.
Related Resources
For broader Canadian crypto tax context, the Canada crypto tax calculator covers the ACB method, the 50% inclusion rate, and Schedule 3 reporting. The Polymarket and Kalshi tax guide goes deeper on the business income vs. capital gains analysis, and the Canada crypto tax deadline page has key T1 filing dates.
For Polymarket traders in other countries: USA - UK - Australia - New Zealand - India - South Africa
Back to the Polymarket tax calculator main page.