A market maker is a firm or individual who facilitates liquidity by standing ready to buy or sell a particular security throughout a trading session. (global.beyondbullsandbears.com)
An option offers its holder the right to buy or sell a particular security at a specific price within a specific time frame. (tsinetwork.ca)
The Financial Industry Regulation Authority («FINRA») and U.S. Securities and Exchange Commission («SEC») define day traders as traders that buy and sell a particular security in the same trading day four or more times in any consecutive five business day period. (traderhq.com)