Activist firm reduces stake in IT company that is being acquired. : Investment firm Jana Partners (Trades, Portfolio) disclosed earlier this week it trimmed its stake in Perspecta Inc. PRSP (NYSE:PRSP) by 18.74%. Taking a value-oriented, event-driven approach to picking stocks, the New York-based firm founded in 2001 by Barry Rosenstein often enters activist positions in order to help unlock value for shareholders. Having previously reduced the position by 29.66% in January, GuruFocus Real-Time Picks, a Premium feature, showed the activist firm divested of another 2.01 million shares of the Chantilly, Virginia-based company on March 2, impacting the equity portfolio by -3.96%.