Business Insider’s Joe Weisenthal says Sotheby’s matters because “Because it’s the ultimate bubble stock, moving violently up and down throughout its history, always making super-sharp peaks right before the economy becomes unglued.”

Says, Weisenthal, “The good news is that if long term history is any guide, the next bubble that’s forming will be even more ridiculous and higher than the last.”

ADDENDUM: Later today, Weisenthal added that more interesting than the “bubbles” were the plummets where Sotheby’s gains seemed to fall back down, during bleak market periods, to its 1989 status. Other stocks, though rising and falling, continue to climb. Are Sotheby’s investors oversensitive to weak markets?