No, five years ago, Filtronic (LSE: FTC) was a penny stock with a share price hovering around 11p. Today, those same shares are changing hands for 250p and the company is worth half a billion. Full-year results are due on 4 August, and that seems like an important date for growth stock investors' calendars. And perhaps key, we could see a PEG ratio (P/E compared to earnings growth) of only 0.7 by then. Growth share investors typically treat anything under 1.0 as a good sign.