His research focuses on companies that have had high bookto-market ratios (B-M), that is, stocks with book values higher than their market values. The reasons for high B-M ratios can be attributed to the financial distress that these companies might be facing. However, using a series of balance sheet and accounting measures, Piotroski developed a methodology to pick gems from this morass. According to Piotroski, the key to improving returns is to avoid the slugs and focus on the quality, high B-M stocks. These stocks can be great investments because their share prices are likely to jump once the market recognises their potential.