There are several ways that a Canadian can invest in a U.S. real estate fund: 

Foreign Investment in Real Property Tax Act (FIRPTA) Withholding: Canadian investors can invest in a U.S. real estate fund through a partnership or a limited liability company (LLC) structure. The U.S. tax code requires that a withholding tax of 10% be withheld on the sale of a U.S. real estate property by a foreign person. This tax can be reduced or eliminated if the investor qualifies for a reduced rate under a U.S. tax treaty with Canada. 

E-2 Visa: A Canadian investor can also apply for an E-2 Treaty Investor Visa to invest in a U.S. real estate fund. This visa allows a foreign national to enter and work in the U.S. based on an investment they will be controlling, while meeting certain requirements. 

EB-5 Visa: An EB-5 visa is a type of investor visa that allows foreign nationals to invest a certain amount of money in a commercial enterprise in the U.S. in exchange for a green card. EB-5 investment can be a good option for Canadians who want to invest in a U.S. real estate fund and gain permanent residency. 

Real Estate Investment Trust (REIT): Canadian investors can also invest in U.S. real estate funds by buying shares of a Real Estate Investment Trust (REIT) listed on a U.S. stock exchange. REITs allow investors to invest in a diversified portfolio of real estate assets, including commercial, residential and industrial properties. 

Canadian-based real estate funds that invest in the US: Canadian investors can also invest in Canadian-based real estate funds that invest in US properties. These funds are typically structured as limited partnerships and are regulated by Canadian securities laws.

It’s important to note that, as a foreign investor, you may be subject to different tax laws and regulations, and it’s always recommended to consult with a tax professional or a lawyer familiar with the U.S-Canada tax laws before making any investments. Additionally, it’s crucial to do thorough due diligence and research on the fund and the market you are considering investing in.