What Is Money? A First-Principles Look at Crypto

Most arguments about Bitcoin, stablecoins, or Ethereum collapse into one deeper disagreement: what is money actually for? You can't evaluate a new monetary asset without a sharp answer to that question. So we'll build one from the ground up, and then look at how each kind of crypto asset measures against it.

The three jobs of money

Economists have converged on three functions money performs. They are distinct, and an asset can be excellent at one while failing at another.

1. Store of value. Can you hold it for a year, a decade, a generation, and have it preserve purchasing power? Gold has done this for centuries. Most fiat currencies have done it for decades, with slow leakage from inflation. Most crypto assets fail this test on short horizons because their volatility is too high.

2. Medium of exchange. Can two parties use it to settle a transaction without friction? This depends on liquidity, network coverage, settlement speed, and finality. Cash is excellent for small in-person trades. Visa is excellent for digital retail. Bitcoin's base layer is slow and expensive for a coffee but settles a $50M transfer faster than a wire.

3. Unit of account. Are prices denominated in it? You'll notice almost nobody quotes the price of a car in BTC. Even crypto-native businesses set fiat prices and convert at the moment of sale. Unit-of- account status is sticky and lags adoption by years.

These three jobs trade off against each other. An asset optimized for volatility-free storage tends to be boring, and boring assets don't attract the speculative liquidity that powers a deep medium-of-exchange network. An asset optimized for fast cheap payments tends to require trade-offs in security or decentralization. Pick two.

Why this matters before you trade anything

If you don't have a sharp answer to "what is this asset for", you can't reason about its price. You'll mistake every drawdown for a catastrophe and every rally for vindication. The fundamental question isn't "will the price go up", it's "is the use case I'm betting on actually being delivered, and is the market pricing that delivery correctly?"

That framing, use-case-first, is what separates traders from gamblers in any market, but it matters more in crypto because the narratives change every cycle.

How crypto assets map to the three jobs

Asset class	Store of value	Medium of exchange	Unit of account
Bitcoin	Strong long-term claim, weak short-term	Slow on L1, fast on L2	No
Ethereum	Mixed, staking yield helps, supply not fixed	Strong for crypto-native apps	No
Stablecoins (USDC, USDT)	Only as good as the issuer	Excellent	Yes (USD-denominated)
L1 alts (SOL, AVAX, etc.)	Weak, high inflation, narrative-driven	Strong on their own chain	No
Memecoins	None	None	None

Notice that stablecoins are the only crypto asset class that genuinely competes on all three jobs, but only because they import the unit-of-account status of the dollar. They are crypto rails for fiat money, not new money.

That's not a criticism. It's the most important fact in crypto: the medium-of-exchange and unit-of-account problems were solved by attaching to the dollar, not by replacing it. Bitcoin is fighting a different fight, to be a non-sovereign store of value. That is also a useful thing for the world to have, and a coherent investment thesis.

A common mistake: treating all crypto as one thing

The single most expensive analytical mistake new traders make is treating "crypto" as a homogeneous asset class. Bitcoin, ETH, USDC, and a memecoin behave nothing alike. They have different drivers, different risk profiles, different correlations to macro, different bear-market behavior. A portfolio that's "100% crypto" is meaningless until you say which crypto and why.

When you size a position later in this curriculum, you'll do it differently for BTC than for an alt. The difference starts here, in understanding what each asset is actually trying to be.

Mental model, the Job-To-Be-Done lens

Borrow this from product strategy: every asset is "hired" by its holder to do a specific job. Bitcoin is hired as digital gold, long-horizon, non-sovereign, scarce. USDC is hired as digital cash, frictionless, stable, fungible. SOL is hired as a high-throughput app substrate. A memecoin is hired as a lottery ticket on attention.

When you evaluate an asset, ask: what job is the market hiring this for, and is the asset doing the job? If the answer is "the market isn't sure yet," you are pricing narrative, not delivery. Both are tradeable, but they are different trades.

Takeaway

Money does three jobs. No crypto asset does all three well yet, stablecoins come closest, by inheriting one of them. Before you place any trade, name the job the asset is hired for. The trade thesis is whether the market is correctly pricing the asset's ability to do that job over your time horizon. Everything else in this curriculum sits on top of that habit.