Easily, and I think it'll happen much sooner than that. Bitcoin's halving schedule tends to accelerate the speculative mania as people realize how impossible it will soon be to accumulate even 1 BTC. The next halving will be in 2020.

At current levels, we are ~38% from the ATH. That's the equivalent of ~ $450 in 2016. From that level, we rose ~43x to the last ATH in December 2017.

So from a logarithmic perspective, and with Bitcoin's huge historic bubbles in mind, $20 trillion is possible. By my fuzzy math, that's about 49x from the current global market cap.