The government will put in $25 billion initially over three years — though Carney didn't say where exactly his government will get that money to put in the fund. Finance Minister Francois-Philippe Champagne was also asked where the money would be coming from and did not answer directly, but he said the federal government's relatively strong fiscal standing internationally would allow it to borrow at favourable rates.
That's one unusual thing about this fund — normally, a country sets up a sovereign wealth fund with excess money they have, according to Brett House, a professor of economics at Columbia Business School. But he points out that Canada has debt, rather than extra money laying around.
See also: https://www.cbc.ca/news/business/canada-sovereign-wealth-fund-explainer-9.7179217