From Longman Dictionary of Contemporary Englishdeal in phrasal verb1 deal in somethingSELL to buy and sell a particular type of product → dealerdeal in shares/securities etc investors dealing in stocks and sharesdeal in drugs/stolen goods etc He then began dealing in heroin.deal in antiques/second-hand books etc2 deal in somethingUSE something to be interested or involved in something As a scientist, I do not deal in speculation.3 deal somebody in to include someone in a game of cards → deal→ See Verb table
Examples from the Corpus
deal in• The article accuses Davis of dealing in arms.• Tax agents are visiting more than 5,000 businesses that deal in expensive items such as cars, boats, and jewels.• Police believe Fry was dealing in narcotics.• Companies that deal in oil should prepare themselves for a price drop.• The gallery deals mostly in paintings but they do sometimes sell photographs.• The police suspect him of dealing in stolen goods.• The main commodities he dealt in were rice, tea, and lentils.deal in shares/securities etc• No longer do you have to go to a bank or stockbroker to deal in shares.• Soon the bullish projections about the speed at which online dealing in shares and unit trusts would grow were being scaled back.• The insider must deal in securities on a recognized stock exchange, which includes dealing in securities through an investment exchange.• In fact dealing in shares or futures is essentially a flair.From Longman Business Dictionarydeal in something phrasal verb [transitive] if a person or company deals in a particular type of product, they buy and sell it as their businesstraders dealing in futuresThe shop deals in high-quality antiques. → deal→ See Verb table 