So i did this: https://gist.github.com/sophacles/a4469f5c656e09e4bc1d

(Note from the end of the chart linked til this month, I assumed the same interest rate).

And found that investing the once a month in a 6 month cd, with a dollar amount equal to the number of days in that month, plus reinvesting the amount coming due (principle + interest) that month from previous CDs, would yeild way less than the market according to this calculator:

In the CD case - just under $90K In the stock case - just under $560K

If my math turns out to be incorrectly done - please let me know I like to learn, but I think I did this right.