Volume 2 of Mr. Kensho's adventures sees him ponder what the present day meaning of value is. What will be valuable, not just today, but forever.

The last 400 days have shown that even established commodities of value such as oil, on which countless empires have been built, may be rendered worthless.

Conversely, save a few bumps and the flickering margins, cryptocurrency has been rising no soaring exponentially.

Eagle-eyed viewers of this volume, would notice that the answer to the titular question is right beneath it, Y£$. This in itself is a play on major fiat currencies today.