Piper Jaffray analyst Matt O'Brien said he views the selloff in shares of Merit Medical after the resignation of Bernard Birkett as CFO as "very much overdone" and encourages "aggressive buying" of the stock amid the pullback. Merit said that Birkett's departure is unrelated to any disagreements with the company and O'Brien said he doubts CEO Fred Lampropoulos will abandon the strategy to improve profitability with the CFO no longer present. O'Brien keeps an Overweight rating and $52 price target on Merit Medical shares, which are down 9% to $50.30 in late morning trading.