On December 8, a firm announces a $2 per share dividend payable to holders of record on December 20, and the dividend will be actually paid in cash on December 25. Which of the following must be correct?

1. The stock price will increase by $2 per share immediately
2. The stock price will decrease by roughly $2 per share on December 25
3. The stock price will decrease by roughly $2 per share on December 20
4. The stock price will decrease by roughly $2 per share on December 18