Relypsa (RLYP) shares have surged more than 58% in early trading after the company agreed to be acquired by Galencia. Galencia will acquire RLYP for $32 per share in an all cash transaction that values RLYP at $1.53 billion.

For RLYP bulls, the offer price would be a disappointment. It is significantly below my fair value for the stock of $48.20 per share. It is also well below what AstraZeneca (AZN) paid to acquire ZS Pharma last year. And remember that RLYP has an approved drug. Still, I believe that investors that entered RLYP at its recent lows should take profit.