When did it last fall over 30 percent and then rise...

When did it last fall over 30 percent and then rise astronomically? Looking for comfort as I bought low single digit and why I kept and liked this stock was that in the last five years it performed excellently with far less volatility in bad times then other stock . This is my first experience of such a massive drop. All without credible reasons. In fact their last advice at a presentation by the company was assuring recently and the big analysts have all recently said every thing looked great. The selling by insiders was minor and the CEO has publicly said he would be divesting a bit yearly a year ago . No surprises look at list of companies with insider selling with larger sales and on hit with massive falls.