Wiktionary
alt. (context business finance English) A transaction in which units of stock or other investment instruments are purchased and then sold within a single market day. n. (context business finance English) A transaction in which units of stock or other investment instruments are purchased and then sold within a single market day. vb. (context business finance English) To engage, as a deliberate investment strategy, in the very short-term trading of stocks or other securities, by selling any given security within the same market day during which it was purchased.
Usage examples of "day trade".
So their research teams had to figure out what future use the cities might be put to, based on resources, proximity to rivers and the sea, what crops grew in that climate, who they might some day trade with, how many people would have to be housed for what industry.
The Trader, apparently certain now that someone was cooperating with him, had dropped his once-a-day trade schedule' and was open for business around the clock.