<prompt> Human: Hello,Ive been making payments on my house for 4 years now, of 420month not including escrow. That would put my total payment since 2013 close to 20k. Thanks to interest early in the loan, only 9k has been applied to the principal. Being that its a 71 ARM at 2.49 but can go as high as 8.99 in 2020, Id like to do what I can to get it paid off quickly without needing to refinance to fixed-rate.My initial plan was to just keep working until I have enough saved to pay it off outright until I noticed that only half my payments currently go towards principal.If I were to make a bulk principal-only payment of, say, 10,000 twice per year, would it significantly affect the amount of interest on future payments? Im sorry this is such a mess, Im bad at organizing my thoughts. Im making good money for the next year or so but I want to reel it back when I can. Loan was initially 84,000, currently at 75,000, monthly payment of 420 towards principal and interest, 71 ARM at 2.49 based on 30-year mortgage. Currently making 1,700-2,300week net but when I scale it back Ill be down to 750week. Thanks for any insight, finances arent my strong spot must be my Greek heritage or something. Im living quite comfortably but could always do better.  <response>: If I were to make a bulk principal-only payment of, say, 10,000 twice per year, would it significantly affect the amount of interest on future payments? Yes. 