Traditionally, "red envelope" cash gifts are given to children during Chinese New Year, which would require withdrawing cash. You can see similar, smaller blips in the M0 graphs of countries like Singapore (which has a large ethnic Chinese population), and South Korea (with two blips per year: Seollal in the beginning of year and Chuseok in the fall). Edit: my friend Jean, who does live and work in China, suggests that this phenomenon may be related to end-of-year settlement business practices, where debts are paid at the end of the year (in cash or cash equivalents) rather than with Net-15 or Net-30 terms.