Funnily enough, given their track record as adversaries, Larry Summers and the Winklevoss twins have something significant in common: They’re both investing in dubious startups. At Silicon Valley VC firm Andreesen Horowitz , “special advisor” Larry Summers (and you thought he was just an economist) has been backing mobile payment schemes. Felix Salmon thinks that most of them will go bust. And the Winklevosses, as you probably know by now, have started a bitcoin ETF, which, if the SEC ever approves it, investors should run from like moviegoers from the Lone Ranger but which will probably make money before it helps spark another worldwide financial crisis.