We explore how large and small banks make funding decisions when system-wide bailouts arepossible. We show that bank size, purely on strategic grounds, is a key determinant of banks’leverage choices, even when bailout policies treat large and small banks symmetrically. Large banksleverage more than small banks because they internalize that their decisions directly affect bailoutpolicies. In equilibrium, this effect is amplified by strategic spillovers to small banks, since banks’leverage choices are strategic complements. Overall, the presence of large banks makes bailoutsmore likely. The optimal regulation features size-dependent policies that disproportionately restrictlarge banks’ leverage.