The New York Stock Exchange originally used a gavel to signal the end of a trading day. This was later adapted to a gong during the 1800s, in order to accommodate for the larger trading floor.
A basket trade is an order to buy 15 or more stocks at once. Basket trades are initiated by large institutions or hedge funds with substantial amounts of money to invest.
A boiler room is an telemarketing operation where sales reps attempt to lure unknowing investors into purchasing micro cap stocks in hopes of securing a hefty commission.