What he's saying is that the pop-up is wrong, not the interest rates. 1.47% of $2bill is $29.4m, so I'd think we'd expect to see $2,029,400,000 in that pop-up, to "plan" for his next investment after the current one ends... or whatever.
What the pop-up is actually showing is this number +1.47%:
[image: i.imgur.com]... and that number looks like it's what his current investment would have been at the rate he invested at (which maybe was 1.39%?), if he had only invested for 1 week.
This mechanic is kinda nice for investments under the $2bill cap, as it shows you what you'll have next time if you just reinvest everything when your current investment is complete .... but for investments above the cap it's confusing. Maybe the pop-up could be changed to use $2bill if the current investment will return more than that? But then people in 10* Oil Rig jobs would have to have a different set of rules for their $3bill cap.