Tried to start this as a convo with you but it didnt work...In regards to IRS and obligations from our discussion on twitter.. My teacher used an example of buying a coffin before you die so your family doesnt have to buy one(morbid I know). So the obligation is on the seller of the coffin who accepts the upfront payment for the obligation to deliver something in the future. The quoted price of the coffin is what the seller of the coffin receives(the short). Since IRS are quoted on the fixed rate side(thats key to me in understanding it) in my mind if I were to "buy" an IRS id be buying that quoted price(paying that fixed interest) and then someone is selling to me the "product" which is floating rate side. So while they are definitely both obligations for me understanding how it was quoted was the big part in understanding the long vs short interpretation. Because at least to my understanding the long pays the quoted price. Perhaps my intuition wouldnt apply to all situations but it makes sense to me in this scenario.