I was just checking my trading accounts today, and I noticed that US dividends (I hold in my Canadian US Dollar investment account) are subject to a 15% withholding tax by the US government.

Foreign (including U.S.) dividend-paying equities are not eligible for the dividend tax credit, so the RRSP is a good place to put these investments. This would also be a good place to hold bonds for the same reason.

Of course, you get a credit when you file your taxes in Canada.

But if you hold these stocks in your RRSP, they are not subject to the same rules.  See this post.

It makes sense as a trader for me also, because I end to keep more "buy-and-hold" and high paying safer dividend stocks in my RRSP (which I trade much less often), and in my non-registered account, I go after more growth stocks and do much more swing trading.