Darvas box theory is a trading strategy that was developed in 1956 by former ballroom dancer Nicolas Darvas. Darvas' trading technique involves buying into stocks that are trading at new highs. A Darvas box is created when the price of a stock rises above the previous high but falls back to a price not far from that high.
In 1956, Darvas turned an investment of $10,000 into $2 million over an 18-month period using this theory. While traveling as a dancer, Darvas obtained copies of The Wall Street Journal and Barron's, but he would only look at the stock prices to make his decisions. It has been said that Darvas was less happy about the profits that he made than he was about the ease and peace of mind that he got from implementing his system. Skeptics of Darvas' technique attribute his success to the fact that he was trading in a very bullish market. They also say that his results can't be attained if this technique is used in a bear market.
The main idea behind Darvas' trading philosophy is to focus on growth industries. These are industries that are expected to outperform the market. Darvas selected a few stocks from these industries and monitored their prices every day. He looked for signs that the stock was ready to make a strong move. The main indicator he used to look for these signs was volume. A significant increase in volume increased the likelihood of a big move. Darvas looked for unusual volume on a handful of companies in industries he expected to grow.
Once Darvas noticed unusual volume, he created a Darvas box with a narrow price range. The stock's low for the time period presents the floor of the box. The stock's high for the time period represents the ceiling of the box. When the stock breaks through the ceiling of the box, the trader is supposed to buy the stock. Likewise, when the stock goes below the floor of the Darvas box, it is time to sell.