Discretionary Trading is decisions made at the discretion of the portfolio manager. The discretionary portfolio manager, investor, or trader, could follow a rules-based method, but ultimately the discretionary trader is making the decisions of what to buy or sell, when, and how much.

Discretionary trading and investing definitions and examples from other sources:

Discretionary Trading seeks to opportunistically participate in market-driven price actions. The final decision about trading is made at the discretion of the fund manager. – Morningstar

Discretionary Trading: Method of trading that relies on subjective (human) entry/exit criteria. – IASG

Also, see:

Systematic Trading

Systematic Trend Following

Keywords: Discretionary Trading, discretionary investing, discretionary trader, discretionary investor, discretionary vs. systematic,