The Globe and Mail reports in its Friday edition that Moody's Investors Service may have downgraded all the Big Six banks, but investors should use any pullback as a buying opportunity. The Globe's David Berman writes that credit-rating agency picked at two raw nerves -- surging Canadian house prices and indebted consumers. As Moody's analyst David Beattie put it, "Continued growth in Canadian consumer debt and elevated housing prices leaves consumers, and Canadian banks, more vulnerable to downside risks facing the Canadian economy than in the past." Bank stocks have been pricing in concerns that Home Capital Group, the struggling mortgage lender specializing in non-prime loans, could fail and lead to contagion within the broader financial sector. Over the past two months, the average bank stock has fallen about 8 per cent, offering a stark reminder that these profit-gushers are indeed vulnerable to a lot of moving parts in the Canadian economy. The last time mortgage delinquencies spiked in Canada was in the early 1990s, when arrears rose above 0.65 per cent of total mortgages in 1992, up from less than 0.2 per cent in 1990. Bank stocks took huge hits during this period, but soon recovered.