We assess the quality of opening and closing prices for Nasdaq stocks by examining the effect that opening and closing call auctions (introduced in 2004) have had on price formation. Our use of measurement intervals of one minute or less sharpens the picture of intra-day volatility...

Volatility is very much with us in today's equity markets. Day-to-day price swings are often large and intra-day volatility elevated, especially at market openings and closings. What explains this? What does this say about the quality of our markets? Can short-period volatility be controlled by...