The Diversification Effects of Initial Public Offerings
从投资组合多元化的角度研究IPO，发现加入市值加权IPO组合能显著扩大投资者的有效边界，使夏普比率平均提高5.50%，且声誉好的承销商发行的IPO是主要来源。
Abstract: A firm's stock becomes publicly tradable through an initial public offering (IPO). This study suggests a portfolio diversification perspective to explore IPOs. We examine whether investors can gain diversification benefits by adding an IPO portfolio to a set of benchmark portfolios sorted by firm size and book‐to‐market ratio. Using US IPOs from 1980‐2002, we find that adding a value‐weighted IPO portfolio does lead to a statistically and economically significant enlargement of the investment opportunity set for investors relative to investing solely in a set of benchmark portfolios. Specifically, the Sharpe ratio of the tangency portfolio increases by 5.50% on average after including IPO stocks. Furthermore, IPOs associated with prestigious lead underwriters are the main source of this augmentation of the mean‐variance investment opportunity set. Finally, our study implies that issuing IPO exchange traded funds or similar products can provide diversification gains to investors.