Specifically, June 2016 went from 5.5% to 5.9%, February 2018 went from 0.0% to -1.0%, March 2018 went from -1.6% to -1.4%, April 2018 went from 2.0% to 1.7%, May 2018 went from 1.6% to 1.3%, August 2018 went from 3.4% to 3.6%, November 2018 went from 2.2% to 2.0%, January 2019 went from 2.5% to 2.7%, and February 2019 went from 0.0% to 0.1%.
Is this due to some tweaking of the algorithm right before the 8/1/19 holding update? It isn’t very significant changes but it does make me wonder, if this sort of thing happens a lot, how much different the returns would have been along the way over the years following the program if there are lots of changes in the program along the way.