In 1945 the economist Friedrich Hayek asked how a whole country learns something only a few people know. Imagine tin gets scarce, he wrote: maybe a mine closed, maybe someone found a new use for it. For everyone else it doesn't matter which. The price goes up, and tens of thousands of people use less tin without anyone telling them why. He called the price system "a mechanism for communicating information".

Fifty years later, small markets of Hewlett-Packard's own employees beat the company's sales forecast in six of the eight forecasts that had one, though twice both were about a third off.

Almost all American orange juice comes from one patch of Florida, around Orlando. In 1984 Richard Roll compared the afternoon orange juice futures price with the Weather Service's forecast of that night's low: when the price rose, the night tended to turn out colder than forecast. The forecast already explained about nine-tenths of the temperature swings; the price knew a little of the rest. Somebody, somewhere, knew something, and the price passed it on.

The lines and the tiles in the video are sketches. Nothing here is trading advice.

What price around you is telling you something?

Sources: F. A. Hayek, "The Use of Knowledge in Society", American Economic Review 35(4), 1945; Kay-Yut Chen and Charles Plott, Caltech Social Science Working Paper 1131, 2002; Richard Roll, "Orange Juice and Weather", American Economic Review 74(5), 1984.
Sounds: our own, made in code (earshot, CC0).