A trader who establishes and liquidates positions within one day's trading, ending the day with no established position in the market. Chicago Mercantile Exchange Glossary
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Speculators who take positions in commodities which are then liquidated prior to the close of the same trading day. Exchange Handbook Glossary
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day trader UK US noun [C]
► STOCK MARKET a person who buys and sells shares on the same day, often on the internet, reacting to small changes in prices in order to make a profit: »
A day trader tries to lock in quick profits by buying or selling a stock in the hope it will keep rising or falling in value for the minutes it is owned.
Financial and business terms. 2012.