Those who win the lottery often spend the money unwisely. This is the risk UBS needs to keep in mind on the anniversary of its Credit Suisse windfall.

A year ago, UBS said it would buy its embattled rival under the auspices of Swiss regulators, who wanted to end a banking panic. UBS ended up paying $3.6bn in stock for a bank with an estimated tangible book value of $33bn — even after write-downs, expected litigation costs and accounting adjustments. The odd skeleton still lurking in the closet probably won’t stop this being remembered as the deal of the decade. Shares in UBS are up 64% since.