Hanover Insurance Gr's stock will likely trade lower on the ex-dividend date, as the market adjusts the stock price to account for the dividend payout. This is a common occurrence for stocks on their ex-dividend dates, as investors who buy the stock after the ex-dividend date will not be eligible for the dividend. The short-term impact on the stock price is expected to be negative, as the stock will likely open 81 cents lower than it would have on any other day.