The yield chapter listed four sources: interest, fees, staking, emissions. One was missing, it exploded through 2025 and 2026, and it is of a completely different nature: lending to real borrowers, with a real risk they do not pay back.
3Jane and USD3: uncollateralized credit, on-chain
Aave makes you deposit $1,000 to borrow $800. 3Jane does the opposite: it lends with no collateral at all, by judging whether the borrower is creditworthy. Like a bank, except the file is a mix of on-chain history, real banking data and a cryptographically proven credit score. An algorithm sets the limit and the rate.
Your place in the queue: senior and junior
On the lender side, you deposit USDC and choose your position in the line:
- USD3, the senior tranche: paid first, repaid first. Lower yield, higher safety.
- sUSD3, the junior tranche: absorbs losses first if borrowers default. Higher yield, in exchange for serving as everyone else's cushion.
That is tranching, straight out of traditional finance. One same package of loans is cut into slices of different risk: the first served accept less yield, the last served demand more. It is a perfectly sane structure, and it is also exactly the one that blew up in 2008 with subprime, when nobody looked inside the package anymore.
The most elegant example in this course
USDai: lending against graphics cards
Yet another logic. You deposit stablecoins, the protocol lends to companies buying GPUs to run AI workloads, and the machines themselves serve as collateral. Idle cash waits in US Treasury bills. The yield, in the low-to-mid teens, comes from operators repaying their loans, not from token emissions. Same two-story structure under other names: USDai is the simple version, sUSDai carries the yield and the risk. Senior and junior again.
The four questions, and they are new ones
Everything else in this course describes risks you can see: a price moving, a ratio falling, a range being left. Here the risk is invisible until the last moment. A loan book looks perfect right up to the day it does not. Four questions for any yield-bearing stablecoin:
- Who is borrowing, and why do they pay this much? A 15% rate means someone accepts to pay 15%. Nobody does that without a reason.
- What happens if they do not repay? At 3Jane, the borrower's score is destroyed and the debt is sold to US collection agencies. At USDai, graphics cards get seized. In both cases no robot saves you in three seconds like on Aave: it is real-world recovery, slow and uncertain.
- Who takes the loss first? If you cannot answer, it is probably you.
- Can I get out? Withdrawals depend on available reserves. While things are fine you leave whenever you want. The day everyone wants out, you wait in line. That is the difference between a liquid asset and an asset that looks like one.
A risk of a brand-new kind: missing a date
Read this one twice