Why would I participate in a stock exchange's opening and closing auctions?

External question — Personal Finance Stack Exchange Author: Flux Original post: https://money.stackexchange.com/questions/132151 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. During the trading day, stock exchanges function as continuous trading markets. The exceptions are the opening and closing auctions. Opening and closing auctions are call markets. As a small retail investor, what are the reasons I would want to participate in an opening or closing auction? What advantages do I get from placing Market-On-Open (MOO), Limit-On-Open (LOO), Market-On-Close (MOC), Limit-On-Close (LOC) orders that I would not get from market orders and limit orders placed during regular trading hours? Are the opening and closing auctions only useful to traders who want to transact large volumes that they are unable to get in the continuous double auction market?