Written opinion delivered by an investment bank to the target's (and sometimes acquirer's) board concluding that the consideration is ``fair from a financial point of view'' to the relevant shareholders. Required as a matter of board-level fiduciary protection in most public-company deals; the analysis (comps, precedents, DCF, premiums paid) is detailed in the merger proxy (SEC DEFM14A) and provides litigation cover under Delaware law's enhanced-scrutiny standards.