For day traders, any profits and losses are treated as business income, not capital. If you're a full-time day trader, you can claim business expenses and also expenses related to your trading. Just like with any other business, you need to have receipts for all the items you declare on your tax returns. The CRA will not accept these kinds of deductions without receipts.
Deductions can include anything from taking stock market trading courses to educational resources, the purchase of a computer, and your monthly internet bill.
For more details, you can go to the link below:
https://turbotax.intuit.ca/tips/how-to-calculate-capital-gains-when-day-trading-in-canada-6251