(USA) A person who informs another person of material information that has not been made public relating to a public company. In the USA, under the Securities Exchange Act of 1934, the tipper is jointly liable with his or her tippee who trades on the basis of the inside information, and is subject to civil penalties of up to the greater of three times the profit gained or loss avoided or $1,000,000, and to criminal penalties of up to 10 years in jail. See 'Tippee'.