Dramatic microstructure changes in equity markets have made standard liquidity measures less accurate proxies of trading costs. We develop trade-time liquidity measures that reflect per-dollar price impacts of fixed-dollar volumes. Our measures (i) better capture institutional trading costs; and...

We develop measures of stock-specific trading activity based on durations of sequences of consecutive trades with fixed cumulative values. Trade sizes and signed-trade imbalances rise with activity, while price impacts generally fall, but not always, due to endogenous variation in liquidity...