Purifying Markets: Alignment Expertise and the Collaborative Production of Global Market Indices

I suggest here the notion of alignment expertise as group-based sets of operations and skills that simultaneously align (1) apparently incompatible worlds, (2) different domains of knowledge, and (3) heterogeneous layers of objects of expertise. The case on which I build the argument is that of market indices. These play a key role in global markets, being illustrative for the data world we live in. Indices are regulatory, epistemic, commercial, and automated objects. These features have to be simultaneously produced and maintained. Based on ethnographic observations in a data analytics firm, I argue that market indices align two very different worlds: the mini-world of econometric formulae and the messy world of computing machines. I identify two operations, grounded in collaborations between software engineers and financial analysts, that perform this alignment: first, a purification operation sorts out price and volume data into “source of truth” and “strange,” respectively. Then, a second purification removes excessive, yet “truthful” data. I argue that these operations are anchored in coordinated expert skills of reading and writing in multiple scripts at once.