Nicolas Darvas was a Hungarian dancer who, as many before and since, was struck by the investing bug in the 1960's. Being a dancer, he was traveling almost always and didn't have either the time or the proximity that Wall Street demanded. Still, the allure of the markets proved irresistable for him.
Even though he couldn't devote as much time as he wanted to his new obsession, he decided to take the plunge. And, like most first-time investors, he lost his shirt. Dismayed by the loss of his savings, he removed himself from the investing game, re-evaluated his strategy, and sat about trying to discover a new way of investing.
His ruminations led him to invent what came to be known as Darvas boxes. This was a simple model to aid in his investment scheme. Darvas boxes are explained in more detail here. Eventually, his methodology led him to make, literally, millions of dollars starting from an initial stake of a few thousand (and this was at a time (the 1960's) when a million dollars really meant a fortune).
Darvas outlines his methodology in a few books, the most popular of which is How I Made $2,000,000 In The Stock Market. Although there are some reports that Nicolas Darvas might have lied about his profits (see here), his method is simple and still has some validity. In fact, combined with the proprietary AI algorithms used in the Sethi Darvas Scanner, it has proved uniquely effective.