I am doing a simple log( c / ref(c,-1) ) calculation, but I am not getting the value that I expect. The calculation is ln( 90.2578 / 90.2353) which is returning 0.000249355 instead of 0.000249317. I checked in the quote editor to make sure there was rounding that I was missing, but I verified on a calculator and in Excel that the value is wrong. What is happening here?

Nothing is â€śhapenningâ€ť except the fact that you donâ€™t understand how floating point works and that actually both numbers are correct. First is 32 bit the other one is 64 bit.