Regulatory debates about centralized trading assume security design is immune to market structure. We consider a regulator who introduces an exchange to increase liquidity, understanding that security design is endogenous. For a given security, investors would like to trade in a larger market...

We study the determinants of asset market fragmentation. We develop a model of market formation with strategic investors that have heterogeneous valuations for an asset. Investors choose a dealer with whom to trade considering their price impact and the liquidity provided by the dealer....