Using a sample of NYSE firms from the first quarter of 2012, we show that the NBBO Depth is negatively affected by quote competition between exchanges and by excess Algorithmic Trading (AT) activity, but positively impacted by volume fragmentation. Trade execution quality also decreases with...

Using a sample of 300 NYSE listed securities and excluding trade reporting facility trades, we examine the impact of order executions inside of the posted spread on market centers, an inside the spread trade(IST). The posted spread on a market center may differ from the National Best Bid and...

Much of the liquidity supply in modern markets comes from algorithmic traders (ATs). Prompted by concerns of fragility induced by such voluntary market making, we examine ATs’ liquidity-provision role during the COVID-19 crisis. We find that amidst the turmoil as market liquidity declined ATs...