Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why is the volume highest at the beginning and end of a trading day?
While volume per trade is higher at the open and to a lesser extent at the close, the overall volume is actually lower, on average. Bid ask spreads are widest at the open and to a lesser extent at the close. Generally, bid ask spreads are inversely proportional to overall volumes. Why this is the case hasn't been sufficiently clearly answered by academia yet, but some theories are that