Does this take into account commission fees ? If I am charged $7 per trade and I invest 1$ per day I am losing 6$ per day to commission. Or are you assuming this is commission free ?
There are a lot of index funds, for no apparent reason the first one I checked was VFINX and it's annual expense ratio is 0.17% which is pretty low compared to the average return over the past 90 years around 10%.
So the actual result would be a little lower, although not staggeringly so.
What would this look like with government bonds?