Abstract Economically insignificant tick sizes encourage undercutting behavior, thus harming market quality. Theoretical work shows that increasing tick sizes in unconstrained markets reduces undercutting and improves market quality. Equity market pricing grids are generally too coarse to test this prediction. We examine a cryptocurrency market with infinitesimal tick sizes where undercutting limit orders acquire price priority without meaningful economic cost. We show that increasing tick sizes reduces undercutting behavior, increases liquidity provision and quoted depth, and reduces transaction costs for institutional and retail-sized trades while decreasing short-term volatility. Tiny tick sizes are suboptimal, supporting increased minimum trading increments in tick-unconstrained markets.

This paper examines the change in the regulatory use of multiple credit ratings after the Dodd-Frank Act (Dodd-Frank). We find that post Dodd-Frank reform, firms are less likely to demand a third rating (typically from Fitch) for ratings near the high yield (HY) - investment grade (IG) boundary to support their new corporate bond issues. Third ratings also become less informative post Dodd-Frank, with a much weaker market impact on credit spreads for firms with S&P and Moody's ratings on opposite sides of the HY-IG rating boundary. We provide new evidence on the effect of Dodd-Frank in curbing corporate borrowers’ strategic use of multiple credit ratings near this boundary.