Year-End Bonus

What Does Year-End Bonus Mean?
A reward paid to an employee at the end of the year. Many year-end bonuses are tied to performance metrics and the amount can vary depending whether certain milestones are met. Year-end bonuses are usually made up of lump-sum payments used to reward the individual for hard work and dedication.

Sometimes called a "Christmas bonus".

Investopedia explains Year-End Bonus
On Wall Street, it is common to see top executives and employees of financial firms receive large bonuses at the end of the year. Bonuses fluctuate depending on the economy and the year's performance, but in most years the amount is substantial.