 And in 2009, he was hired as a consultant to Christian Birkenstock at a time of high drama at his 250-year-old namesake company. Reichert became CEO in 2013. Since then, the sales have skyrocketed. The Birkenstock brothers are now billionaires, and the stock's up more than 25% since its debut on Wall Street last October. I kind of think it requires such a character to kind of wade into this family drama. Nathan Hager, Bloomberg Radio.