The market that scares the bejezzus out of me is the commercial property market. Every bank in the UK has massive portfolios of loans leveraged to the 9's vs commercial property with returns calculated on rentals. At the same time high streets are emptying left right and centre. If rents come down then shops can compete, but if rents come down then the bank loans all go south via breached covenants. If rents don't come down the income to service the loans dries up as shop after shop goes out of business due to "internet".