The program is calculating the nominal return on the beginning of the year balance inputs and showing in the reports the end of the year balance. Earnings on Regular Assets are shown in the Income Overview report. Earnings on Retirement Accounts are shown in the retirement account reports.
As we approach the end of the year, uses ask: Is there is a way to adjust for what seem to be known returns for the current year? They want to assume, say, not the default 3.5% but rather 12%. There is a way but do remember, to take 2018 as an example, when US Stocks dropped 14.28% from Oct 1 - Dec 31 2018. The year's not over til it's over.
That said, the program in Settings and Assumptions does allow you to indicate the the rate of return will change. So you could indicate that 2019 return is 10% (percentages higher than 10% are not currently permitted, but this will be changed in the near future), and that starting next year (2020 when this document was composed) and after it will change back to 3.5% or 4%. One can make these adjustments in both regular asset and retirement asset settings in Settings and Assumptions.
In the new year, January 1, you should update balances to accurately reflect their current levels as well as mortgage balance and years remaining. After Jan 1, small alert flags will appear for input items you should check to see if they need updating for the new year.
One feature request that is in the works will allow you to input current balances at any point in the year and the program will prorate and calculate the first year based on the current date instead of Jan 1 from the beginning of the year.