Much of economic and social life depends on experts who draw on their unique knowledge and specialized practices, many of which are invisible and obscure to clients, to make decisions and solve problems. However, experts increasingly find themselves in situations where their clients may possess similar knowledge, experiences and familiarity with expert work practices, raising questions about expert authority. Yet we know little about how experts contend with and manage overlaps in knowledge with their clients, and with what consequences. In this paper, we inductively study the work of two equity research analyst teams who serve large institutional investors. By tracing their work over a decade through approximately 680 reports covering the same 5 publicly-traded firms, we found that these groups varied in what we call their “relational stances” toward clients, which held important consequences for how they articulated and framed their valuation practices. While one group sought to differentiate its expertise from clients and framed its practices as conceptually superior, the other accommodated and mirrored client preferences while framing practices as pragmatic solutions to specific market contexts and challenges. These differences led the two groups to adopt different trajectories of practice change which varied in how they introduced, adopted and used valuation methods across the same set of companies.