<prompt> Human: I graduated from college last year, and I currently am paying off a loan to my father for a portion of my tuition costs. Here are the details: Initial Balance: 23,364.63 Interest Rate: 4 Payment Period: 12 years 144 months First Payment Date: September 1 2012 Monthly Payment: 205.68 Current Balance: 21,536.18 Principle Paid to Date: 1,955.82 Interest Paid to Date: 1,129.37Earlier this year I also inherited about 100,000 from another family member. Although I initially thought about paying off my loan in full, I elected not to because my father wasnt stressing the loan he thought it was important for me to have liquidity in this job market and because I thought I could do better than a 4 return in the market I have.However, I spoke with him the other day, and he mentioned if I wanted to pay off the loan early, he would let me pay off the principle directly in the monthly increments already specified by the loan and effectively skip the interest payment for that month.It seems to me that since the interest payments are front loaded for the loan, and the principle payments are back loaded, I could achieve a higher rate of return than I can in the market by paying off part of the loan.If I were to just use the next month as an example, if I were to pay off the loan early I would invest 133.89 in principle payment to earn 71.79 in skipped interest payment a return of 53.The farther in advance I pay off, the lower the return is, but I imagine I could target a certain return and pay off to that number.Is there something big that Im missing?EDIT:Below is what Im attempting to describe - heres what my payment schedule would look like if I prepaid the next 5 payments:ORIGINAL AMORTIZATION SCHEDULEBalance Payment Interest portion Principal portion End balance---------------23,3642067812823,23623,2362067712923,10723,1072067712922,97822,9782067712922,84922,8492067613022,71922,7192067613022,58922,5892067513122,45822,4582067513122,32722,3272067413222,19522,1952067413222,063REVISED AMORTIZATION SCHEDULEBalance Payment Interest portion Principal portion End balance---------------23,364128012823,23623,236129012923,10723,107129012922,97822,978129012922,84922,849130013022,71922,7192067613022,58922,5892067513122,45822,4582067513122,32722,3272067413222,19522,1952067413222,063  <response>: What on earth are you talking about? 