Well, as we get closer to the end of the month we'd expect to see less movement in the charts. A single day of sales will impact the month-to-date rankings when you're only a few days into the month than when there's only a few days left in the month. Furthermore, we're moving away from tax season and into the slow weeks of spring, so March as a month could be more front-loaded (and VGC usually shows it is, barring any March games that move hardware), which means that sales in later weeks in the month will have an even smaller impact on the overall monthly ranking.
If you want, I could whip up a chart tracking the change in the monthly positions for the PS4 & XBO this month.
Don't need to do this, i was following this thread the Whole Month, Xbox One, will have a Hard time, because who is interested in it might wait the Xbox 1.5, and with all the games coming for PC, it will Impact sales on the Future.