Again, though, derivatives offer the best example of the incorporation of finance theory into the linguistic infrastructures of markets. Options market participants talk all the time about "implied volatility": indeed, option prices are sometimes quoted not in dollars but in implied volatilities. "Implied volatility" is an entirely theoretical notion, calculated by running an option-pricing model such as Black-Scholes "backwards" to determine the volatility of the underlying asset implied by option prices.

Donald MacKenzie, An Engine, Not a Camera, loc. 1130