Do Market Makers Suffer from Splitting Headaches?

Studies of transactions surrounding stock split ex-dates often conclude that splitting firms either experience a decline or an improvement in their stock's liquidity, based on independent measures of trading costs and trading activity. In contrast, our evidence suggests that splits from outside into what often is deemed to be the “optimal” stock price range of $10.00 to $39.99 are “nonevents” for market makers: The spread-setting behavior of the market does not change after a split. Our analysis accounts for the interdependencies between bid-ask spreads and market microstructure effects and distinguishes between optimal and all other splitting firms.