September seasonals: It's a tough time for stock markets

Another reason to worry about Canada

September is a tough time in global stock markets. Since 1990, it's one of only four months where the S&P 500 averages a decline.

One index that's particularly soft in September is Canada. The TSX Composite Index averages a 1.28% decline over the past 28 years and it's by-far the worst month over 10, 20 or 30 year periods.

Combine that with worries about NAFTA and trade wars and it could be a tough month overall for Canadian stocks. Note, however, that the weakness doesn't extend to the Canadian dollar. It's generally a middling month for the loonie.

It's also a soft month for Japanese stocks and it's the third-worst month for the UK FTSE 100.

Another way to play it is to buy on weakness in September because the Oct-Dec period is strong in just about every global index.