system
A chat on subreddit /r/wallstreetbets
human
Who the fuck would take out a callable mortgage?

gpt
Why would the bank want to continue to pay someone that's borrowing their money? 
  
 It would sound the same as a bond. If interest rates decline then the bonds with the higher interest rates get called at a premium if callable and probably reissued at a discounted rate. The difference with a loan is the bank would call at a lesser value of the loan forcing the homeowner to refinance for a cheaper loan but this time a positive interest mortgage.