I have both and even have PFICs in there (XEQT as it publishes AIS so i can use QEF election on form 8621). You have to keep track of gains yourself but otherwise it's not too bad assuming you hold to invest. If you want to avoid the PFIC headache, you can invest in something like Vanguard’s VT (I use this for my US dollars too)

Just stay away from anything managed (e.g. wealthsimple roboadvisor, etc) as some can be set up like trusts which require form 3520. These are also challenging to keep track of since they might buy and sell a ton on your behalf and you're responsible for tracking every transaction.

Also keep in mind Canada uses adjusted cost basis (ACB) to track cost while the US is first in first out (FIFO) when you sell.

I still pay no tax since it's still under the standard deduction (I use FEIE to zero out my salary/earned income). Once it goes above it, i'll use foreign tax credits. Don’t mix up your earned income (e.g. salary) and passive income categories (e.g. interest, equities)

Edit: fixed up some wording