According to a Bank of Canada report:

Investors were responsible for 30 per cent of home purchases in the first three months of the year, according to data released by the Bank of Canada. That is up from 28 per cent in the first quarter of last year, and 22 per cent in the same period in 2020. The central bank defines an investor as a buyer who took out a mortgage to buy the property while maintaining a mortgage on another home.

The effect of investor buying is:

“During housing booms, greater demand from investors can add to bidding pressures and intensify price increases,” said the note. “Similarly, when prices are stable or declining, a lower influx of investors can add downward pressure on housing demand and prices.”