From hero to zero: Evidence of performance reversal and speculative bubbles in German renewable energy stocks

► We examine the return behavior of German renewable energy stocks between 2004 and 2011. ► The former fad stocks have recently turned into loser stocks. ► They produced significantly negative Carhart four-factor alphas since 2008. ► The price behavior before 2008 was considerably driven by explosiveness. ► Upbeat sector sentiment in the mid-2000s might have caused this speculative bubble.