How does Mergerstat determine an unaffected stock price?
Mergerstat looks at the trading volume and stock price fluctuations for the year prior to the date of announcement. If they discover there is a significant change in stock trading activity, they conduct research to determine the reason for such changes. If the reason is due to potential M&A activity (i.e. the target company has hired a financial advisor to seek buy-out opportunity, or the target company is in talks with potential buyers), then the earliest date before such announcements will be selected as the unaffected date, since this date is representative of normal pricing activity. If no talks or rumors were disclosed prior to the announcement, one day prior to announcement will be selected as the unaffected date. The Mergerstat unaffected stock price is the stock price on the unaffected date.
