According to standard democratic theory, expert authority is legitimate when constrained to finding technical means to political ends set by electorally accountable bodies, hence the dominant principal-agent perspective on the accountability of experts and concerns controlling that delegated ends have been appropriately pursued. In a novel normative argument, we propose an alternative model to the strict division of labour that characterises principal-agent approaches, which we refer to as mutual attunement. This political form of mutual attunement between the elected and the unelected has democratic merits. Whereas the traditional focus on control and backward-looking accountability captures part of the picture, we argue that legitimacy also requires interaction that proceeds on a foundation of shared meanings and sensitivity to various kinds of uncertainty. Moreover, this interaction is reciprocal and forward-oriented. To evaluate our reasoning, we construct a set of innovative measures that we assess following an in-depth analysis of hearings with the European Securities and Markets Authority in the European Parliament’s Committee on Economic and Monetary Affairs. In support of our argument, the results show how financial regulators provide advice on political ends as well as means.