you are so right, but nothing succeeds like success and the victors write the history.
It is just as possible that something seriously went wrong that we dont know about
but it didnt and the sun came up on Wed. Goody.
In a simple matching market like some extended hours trading platforms, there must be a sell for every buy.
On exchanges such as NYSE and NASDAQ, the other side of the trade is handled by a specialist or market maker. When I sell or buy, I am not trading with another buyer or seller such as myself, I am transacting w a specialist or MM.