1. One of the variables that can be used in an option-pricing model.

2. An acquiring company's continuation of the target company's outstanding stock grants. Assumption of the selling company's grants allows the target's employees to receive stock in the buyer when their restricted stock/RSU grants vest or when they exercise their stock options or SARs. All terms and conditions of the grants continue after assumption by the acquirer. In an assumption, the buyer is continuing the seller's stock plan and the shares available under it, as opposed to a substitution. For details, see the FAQS in the section M&A: Impact on this website.