Chamath Palihapitiya's tech pedigree and iconoclastic pronouncements about investing made Social Capital one of the most buzzworthy venture-capital firms of the past decade. But the firm stopped raising new funds two years ago after angering some of its own investors, who watched a series of changes in the investing strategy lead nowhere. Now the venture capitalist has found a new investment vehicle that may be better-suited to his ambitions: the SPAC, or special-purpose acquisition company, a type of company raises funds through an IPO that can then be used for acquisitions.