Stabilization Activities by Underwriters after Initial Public Offerings
研究发现承销商在IPO后通过空头回补、限制抛售和选择性使用超额配股权来稳定股价，而非仅靠稳定出价。平均空头头寸占发行股份的10.75%，在16.6天内通过22笔交易平仓，损失占承销费的3.61%。
Prior research has assumed that underwriters post a stabilizing bid in the aftermarket. We find instead that aftermarket activities are less transparent and include stimulating demand through short covering and restricting supply by penalizing the flipping of shares. In more than half of IPOs, a short position of an average 10.75 percent of shares offered is covered in 22 transactions over 16.6 days in the aftermarket, resulting in a loss of 3.61 percent of underwriting fees. Underwriters manage price support activities by using a combination of aftermarket short covering, penalty bids, and the selective use of the overallotment option.