The options traders who used Black's sheets or other implementations of the Black-Scholes-Merton model hoped, of course, to make money. The most obvious way of doing that was to put into practice the arbitrage strategy inscribed in the model's derivation. One could use the model to identify options that were overpriced (or underpriced) relative to their theoretical values, sell them (or buy them), and hedge the risk by taking and adjusting a position in the underlying stock. Black's sheets included not only theoretical prices but also the "delta" values that told subscribers how big that hedging position in stock should be.

Donald MacKenzie, An Engine, Not a Camera, loc. 731