Do banks actively seek assets that are widely held across the financial system? We measure the extent to which sovereigns are systemically linked by a common bank investor base, and show that banks have a unique preference for funding commonality. Banks are 10% more likely to hold bonds of more commonly funded sovereigns, consistent with the anticipation of regulatory coordination in the event of distress. A structural portfolio demand system quantifies the bond pricing implications of this preference. Counterfactual analysis shows that in the absence of these preferences, borrowing costs would increase, raising yields by about 1% on average.