Abstract During 1989 the Ashridge Strategic Management Centre undertook some research, in conjunction with Wallace, Smith Trust, into the phenomenon of ‘value gaps’. An article on the subject was published in Long Range Planning in August 1990 and a joint conference with the Strategic Planning Society was held in October of the same year. This article has been edited by Sally Yeung of the Ashridge Strategic Management Centre from a speech given by Richard Koch at the conference. Koch gave a spirited defence of the virtues of raiders as a means of closing value gaps, and has harsh words for managers and institutional investors. While we would not agree with all of Koch's views, we believe that his arguments are challenging and provocative, and hope they will stimulate further debate on the subject of value gaps.