What Stablecoins Are: Back to the Hierarchy-of-Money Table

Part VI · New Rails (Chapters 26–28) Builds on: Chapter 2 (the split between clearing and settlement), Chapter 3 (the hierarchy of money, the liability view), Chapter 19 (the question left hanging), Chapter 25 (ledgers) New concepts in this chapter: stablecoin, reserve assets, shared ledger, on-chain settlement, tokenized deposits

This chapter calls on concepts from nearly every chapter before it. If any step refuses to parse, go back and patch the chapter it came from.

1. The Question the Previous Chapter Left Open¶

The previous chapter closed with a promise: Part VI would face, head-on, the question left hanging at the end of the Wise model — whether there is an asset that any two parties anywhere in the world can transfer instantly, without parking a pile of money in every country. Before answering, this asset — the stablecoin — has to go back into the table from the hierarchy of money: whose liability is it?

Answer that first.

2. Putting Stablecoins Back in the Hierarchy of Money¶

Take USDC. Circle issues it, and the reserve assets are short-term US Treasuries and cash held at banks.

In the format of the table from the hierarchy of money:

The conclusion, straight out:

In the hierarchy of money, stablecoins sit on the same layer as e-wallet balances.

A stablecoin is one company's liability, and its ability to pay depends on that company's reserve assets. It is not a "new kind of money," and it is not a "digital dollar" — it is an IOU, issued by a private company, backed by reserves of dollar assets.

The line planted back in the hierarchy of money can now be cashed in: in the hierarchy of money, stablecoins innovate nothing.

So where is the innovation?

3. The Innovation Is the Shape of the Ledger¶

The nature of payment said a payment is an edit to a ledger. Clearing and settlement said the interbank problem exists because each bank can only write in its own book.

A blockchain changes exactly that one condition:

It provides a single shared ledger that every participant can read and write directly.

No one has to run a clearing house, no one has to net positions, and no universally trusted middleman has to hold the settlement asset — because everyone is writing in the same book.

The N² problem from clearing and settlement — every pair of institutions needs its own connection, and the number of connections grows with the square of the institutions — gets bypassed here. Not by "everyone settles with the same hub," but by "everyone writes the same book."

The direct consequence of that one condition is the most tangible selling point stablecoins have.

4. Clearing and Settlement Finish Together¶

Clearing and settlement taught one line: every time you meet a new rail, ask when clearing happens, when settlement happens, and how long the gap in between is.

Run that measuring stick down the list:

An on-chain transfer merges clearing and settlement into one act. On this point it belongs in the same family as Fedwire — but Fedwire runs only inside the US, only during business hours on business days, and only for banks that hold reserve accounts.

An on-chain transfer has none of those three restrictions. That is where the real difference lives:

Look at the last row. That is the price of the trade: to buy the freedom in the first four rows, the settlement asset gets downgraded from a central bank liability to a private company's liability.

The hierarchy of money said it: the lower the layer, the more usable the money — and the more credit risk you carry. Stablecoins are a textbook case of that sentence.

5. Reserve Assets: The Only Way to Judge a Stablecoin¶

Since a stablecoin is the issuer's IOU, you judge it with the two questions from the hierarchy of money: who owes you? What do they redeem with, and where are the reserves?

Concretely, four things to check:

The fourth is the easiest to skip and the most critical.

If only a handful of institutional clients can redeem 1:1 directly with the issuer, then for the ordinary holder the price is set by secondary-market supply and demand — under stress, "1 coin = 1 dollar" is a market expectation, not a contractual right.

There has been one textbook demonstration. In March 2023, Silicon Valley Bank failed. Circle, the issuer of USDC, had about $3.3 billion of reserves at that bank, and through the weekend nobody could confirm whether the money would come out. On the secondary market, USDC dipped to around $0.87. The reserves themselves lost nothing — the FDIC then announced deposits would be covered in full, and the price was back near $1 by the next business day. What depegged wasn't the reserves. It was the redemption channel: banks don't open on weekends, so nobody could redeem.

So when you size up depeg risk, the first thing to check is not whether the reserves are sufficient. It is how fast those reserves turn into cash under stress. That is not a technology question — it is the ability-to-pay question from the hierarchy of money.

6. Stablecoins vs. Tokenized Deposits¶

In 2026 this comparison started to matter, because the banks began hitting back.

A tokenized deposit is this: a bank moves its own deposits onto a chain so they can be transferred programmatically — but they are still bank deposits.

The largest US banks are jointly pushing a tokenized-deposit network, operated by The Clearing House, targeted to go live in the first half of 2027.

(Starting here, these three chapters cite a run of industry facts — product timelines, partner lists — all drawn from the companies' public announcements. This field moves every quarter; look up the current state when you need it. What the course wants you to keep is the structure, not the numbers.)

Look at who the operator is. The four US rails covered The Clearing House: the institution owned jointly by the big banks, the one that runs RTP. The same people, the same organization, lifting the way they solved domestic instant clearing twenty years ago and pointing it at on-chain settlement.

A side observation falls out here for free: when incumbents fight new entrants, the weapon is usually not a ban — it is the same product, built one layer higher. The banks did not lobby to kill stablecoins. They moved their own deposits onto the chain instead — just as programmable to transfer, but one layer above stablecoins, with deposit insurance attached.

7. The Question This Chapter Leaves Open¶

By now, what stablecoins are is settled: no innovation in the hierarchy of money, real innovation in the shape of the ledger, and the price is a settlement asset one layer down.

But the question from the Wise model still isn't fully answered. The original wording:

Is there an asset that can move instantly between any two parties on earth, with no pile of money parked in every country?

The first half is answered: yes. And the second half? If no money sits parked in each country, how does the user finally turn the money into local currency in hand?

Of the four cost items in the four cost sources, which do stablecoins actually cut — and which do they add?

The next chapter runs the measuring stick from the Wise model over it: where does it move the cost from, and where does the cost go?

8. Self-check questions¶

1. Using the liability view from the hierarchy of money, state exactly what you hold when you hold 1,000 USDC.
2. Why do on-chain transfers and Fedwire belong to the same family, yet differ enormously? List at least three dimensions of difference.
3. Tokenized deposits sit above stablecoins in the hierarchy of money — so why do stablecoins still have room of their own?

9. Answers¶

Answer for yourself before reading on.

1. You hold Circle's debt to you of $1,000, and its ability to pay is backed by the short-term US Treasuries and bank deposits Circle holds. You do not hold dollars themselves, and you hold no direct claim on any bank or central bank. The 1,000 tokens on-chain are the certificate of that claim and the way it moves — not the claim itself. If the issuer's reserves fall short or the redemption channel closes, the tokens still transfer on-chain just fine; they just won't fetch $1,000 back.

2. What they share: clearing and settlement finish together, and arrival is final — none of the exposure window from clearing and settlement. At least three differences:

   • Operating hours: Fedwire runs business hours on business days; the chain runs 24/7.
   • The entry bar: Fedwire is open only to institutions holding central bank reserve accounts; the chain is open, in principle, to anyone.
   • The settlement asset's layer: Fedwire settles in central bank reserves, a central bank liability; the chain settles in a private issuer's liability.

   The first two are the gains. The third is the price.

3. Because the tokenized deposit buys its higher layer with closedness. It is one particular bank's deposit, so only that bank's customers can hold it; using it across institutions requires the banks to build interoperability arrangements first — which is, at bottom, the clearing problem from clearing and settlement all over again.

   The value of stablecoins is precisely the openness: any person, any institution, any country can hold and transfer them directly, without first becoming anyone's customer.

   So the two serve different scenes. Large-value settlement between institutions will lean toward tokenized deposits; scenes built on long-tail users (many people, small tickets, the scattered customers banks can't be bothered to serve) and emerging markets remain stablecoin turf.

Previous: Chapter 25 · Ledgers and Reconciliation: The Real Skeleton of a Payment System Next: Chapter 27 · What Stablecoins Solve — and What They Don't