That would require a daily growth of $4.50, starting from $30, to achieve $5000 by '21.
I'll save the maths for someone else, but I don't think that could be achieved with a maxed daily growth of +5% under volatility control (let alone if they're pegging the control to weekly volatility) combined with the annual 42.7% intended growth to the coin's base value.
Not without any volatility, anyway.

I could be wrong. I wouldn't mind if I was wrong. The idea of being a multi-millionaire in a few years is pretty damned appealing.  Just offering a bit of a reality check to counter the hype.