One of the reasons that there are currently so many stock exchanges in the US is that while you aren&#x27;t allowed to quote at subpenny levels, if you have several exchanges with different levels of make&#x2F;take fees, you effectively have the ability quote (or remove liquidity) at subpenny price levels <i>net of fees and rebates</i>. In that scenario the proliferation of exchanges is less about competition and more about finding clever ways of negotiating the regulatory environment.