After Boston Scientific announced an agreement to acquire BTG plc for $4.2B, Stephens analyst Chris Cooley compared the "unexpected" deal to BSX's previous successful acquisition of AMS. As in the case of AMS, the Street is "surprised" by the scale and "out-of-the-box" nature of the proposed acquisition, but the company's core growth and margin profile will be enhanced and it will still have the ability to pursue more tuck-in acquisitions, Cooley tells investors. Following the deal announcement, he reiterates his Overweight rating and $42 price target on Boston Scientific shares.