We describe four channels through which breakups can potentially increase idiosyncratic volatility for parent firms. These are: loss of diversification (portfolio effect), change in growth opportunities, change in operational efficiency, and the flow and assimilation of information (information effect). The relevance of each channel depends on the mode of a breakup. We explain conceptually and show empirically, using a sample of 530 breakups (259 spinoffs and 271 equity carveouts), that the portfolio effect is dominant for spinoff parents, while the information effect gains importance for carveout parents. Our novel insight is that the magnitude of the information effect depends on the pre-announcement information set held by investors; we provide a simple state-space model and empirical evidence to support this intuition. We also find a relation between the change in operational efficiency and the change in idiosyncratic volatility for spinoff parents.

We examine the role played by the parent’s motive in undertaking a carve-out; the parent’s post-IPO influence over the carved-out subsidiary; and anti-takeover provisions and industry structure of a carve-out on its acquisition likelihood and its acquisition premium. We find that the probability and hazard of a carve-out acquisition increase when the parent’s objective is to unlock the value of a subsidiary and when the parent and the subsidiary are tied with a product-market relationship. We also find that the post-IPO parent ownership significantly affects the acquisition likelihood and the level of acquisition premium. Additional analyses examining the post-IPO carve-out status suggest that the product-market relationship and post-IPO parent ownership increase the probability of re-acquisition.