What this is
Broadly four: (1) market-neutral trading income such as funding-rate basis; (2) protocol-set savings rates governed by votes; (3) real-world asset interest like T-bills and bank deposits; (4) lending interest from institutional or compute borrowers. Many products blend more than one.
What it means for your yield
Each source has its own bad weather. Basis income thins out when funding flips negative; savings rates change by vote; T-bill yield follows the Fed; lending income depends on borrowers staying solvent. Knowing the source tells you when the yield gets worse — and whether a falling rate is mechanical or a warning.
Where it appears on Pennyworth
The APY hero on every detail page lists the product’s yield sources as chips, with minor or incentive components tagged separately.