I had similar thought while creating this thread but, had to abandon ship because when you look at it, we still need to shift values into a more generally acceptable forms to enjoy the benefits of having taken up certain investments.

So the idea was,
I got 0.5 BTC valued at $100 in 2015
Same 0.5 BTC is now valued at $120 in 2018.

Haven’t made a profit of $20, to enjoy that profit, I’ll still end up liquidating some of my original 0.5 BTC. Let’s say, 0.05 BTC is valued at $20. I’ll be deducting that from 0.05 BTC from the 0.5 which means,

0.5 BTC - 0.05 BTC = 0.45 BTC
Hence, 0.45 BTC would retain the $100 value in 2018.

What have we done, we have liquidated.

Same logic apply to every other investments. You’ll always end up selling a portion of what you are invested in to enjoy the profits. $100 in the bank will always remain $100. Invest it in let’s say,

10 wrist watches = $100 in 2015
Now, same 10 wrist watches = $200 in 2018

To get the profit, you’ll have to sell 5 of it.
And be left with 5 which would be valued at $100.
Same capital, reduced quantity.
However, valued has switched from commodity to money.