Painting the tape refers to

the practice of buying large amounts of a security to drive its price up artificially.

the illegal activity of a group of investors who buy and sell a security among themselves to create an artificially high volume of trading in hopes of luring investors to buy the security.

the prohibited practice of excessively trading on a client’s account that is used by some broker-dealers and/or their agents to generate more commissions for themselves.

the unethical practice of investment advisers who issue “buy” recommendations for stocks that they own themselves without disclosing the fact.