Arrowhead Pharmaceuticals shares have recently come under pressure, down 27% year-to-date, despite no company-specific developments, B. Riley FBR analyst Mayank Mamtani tells investors in a research note. The analyst believes valuation and competition remain two components of a bear thesis. However, these are inflated if one were to do a bottom-up fundamental analysis of only the company's five most-advanced programs, contends Mamtani. The analyst recommends investors take advantage of the recent share pullback, believing an "attractive catalyst profile" will help drive a rebound from these levels. He reiterates a Buy rating on Arrowhead with an $83 price target.