I fully understand where Bankish is coming from.  No question the Big 6 bank have delivered.  The problem is that despite their relative protected status in Canada they aren't immune.  During the late 80s when Royal Trust went under 2 of the Big 6 banks were also in significant trouble.  While the information has never been formally made public CM and one other bank were considered at risk of failing.   I certainly don't lie awake worrying about it but it does help shape my investment process.

I own 5 of the Big 6 and they comprise about 15 - 20% of the portfolio making them collectively one of the biggest holdings.  But I can find similar dividend yields and growth in other sectors that allow me to reduce my portfolio risk.  I also own a number other dividend payers that while higher risk substantially boost my dividend yield from the 4 - 5% bank yield to over 6%..