Can I still use the capital gains exemption if my company owns an investment portfolio?

Maybe, but a significant investment portfolio is exactly the kind of asset that can put the exemption at risk. The Lifetime Capital Gains Exemption shelters capital gains an individual realizes personally on a sale of qualifying small business corporation shares, and qualification depends on tests looking at how much of the corporation's assets are actually used in an active business in Canada, not just held as passive investments, both at the time of sale and over a preceding period.

A large investment portfolio — stocks, bonds, GICs, or similar passive holdings — counts against the "active use" side of that test. If passive assets grow large enough relative to the business's active assets, the shares can fail to qualify at all, meaning the exemption isn't available on the gain even though the underlying operating business is perfectly healthy.

This is where "purification" comes in: cleaning non-active assets off the balance sheet, often by distributing them out or moving them to a separate holding company, before a sale, so the shares being sold qualify. Because the tests are fact-specific and time-sensitive, this needs to be reviewed with an accountant and a lawyer well before a sale is agreed, not after.