Published online by Cambridge University Press: 13 October 2022
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.
We thank Angelo Aspris, Patrick Augustin, Jennifer Conrad (the editor), Amy Kwan, Albert Menkveld, Bernt Ødegaard, Peter O’Neill, Richard Phillip, Talis Putnins, Barbara Rindi (the referee), Andriy Shkilko, Elvira Sojli, Ingrid Werner, Bart Yueshen, Zhou Zhong, and Marius Zoican as well as seminar participants at VU Amsterdam, FIRN Australia, University of Western Australia, Wilfred Laurier, and McGill for useful comments and suggestions. Dyhrberg acknowledges financial support from the Capital Markets Cooperative Research Centre.