system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do stock exchanges close and then reopen every day?

Is there any reason they can't stay open 24/7?
gpt
Historically people traded on the floor of the stock exchange, so it made sense to have business hours for all of the reasons that other places have business hours -- traders went home for the night, the place needed to be cleaned, etc.

Over time, practices evolved around a set trading timeline. Companies report quarterly results early morning before the market opens so that everyone can have time to understand it before trading starts for the day. Big events are generally announced at the end of the day so that people can digest it over night before the market opens the next morning.

This take a bit of the competition to be *the first* to know info to try to beat the market and levels the playing field a bit. It also takes some of the panic buying/selling out of it and, at least theoretically, leads to fewer big swings and a smarter market. Someone can read the whole press release without trying to make an immediate decision about whether to buy/sell before everyone else does.