The stock ticker’s real-time price data created the possibility of chartist technical analysis.

Evidence

The overall causes of practitioner ire were, above all, the random-walk hypothesis and the efficient-market hypothesis. They were a direct challenge to the two dominant schools of thought among investment professionals: “chartism” (or “technical analysis”) and “fundamentals analysis.” Chartism was in a sense a by-product of the rapid development in the late nineteenth century of the technology for recording and disseminating securities prices, notably the stock “ticker,” in which prices were recorded on exchanges’ floors, transmitted telegraphically, and printed out on paper tape in brokers’ offices. With prices available in close to real time, it became possible to construct charts of hour-by-hour fluctuations. — Donald MacKenzie, An Engine, Not a Camera, 334

Categorization

• XREF: Echoes McLuhan-style medium-determines-method arguments and connects to claims about how price recording/dissemination infrastructure shapes market practice. — connects to: Machine-readable price data transformed finance research from hand compilation to analysis — Donald MacKenzie, An Engine, Not a Camera: How Financial…, 309
• ADDENDUM: The ticker as an infrastructural precondition for a school of market practice parallels how the trees article treats grafting infrastructure as enabling entire practices.

Broader Connections

• Machine-readable price data transformed finance research from hand compilation to analysis #expands (0.85) — Donald MacKenzie, An Engine, Not a Camera, 309