Hello Mr. Joo,
I am sorry that I do not have Korean fonts on my computer now.
I have 5 year ARM loan of 560k at 3.25%.  
Property value: $1.3 million in Los Angeles City
Principle & Interest= $1000/$1500
Property interest and home insurance (no HOA): 1000
We plan to refinance to 15 year 450k in 3 years.
A Question
1) Do you think it is wise to making extra payments toward mortgage eg $1000/month to reduce Principle Balance and reduce Interest (even small bit) OR Invest the money for possible increased return in 3 years (I know the possibility of losing value of investment or not gaining any return)
Thank you very much.