There are 2 ways for that.
If monthly contribution, you can purchase more units if there are alot of fluctuation on the market. However, in return you will gain less if the market is moving upward
If annually contribution, you will earn more if the annual performance is positive growth, however, you will loss more if it has a negative growth.
Lastly, most of the agent will ask you to do annual payment for first year, because they can receive the commission at 1 time.
if you have more questions, feel free to email me
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