Trading, AFS, and HTM compared
| Classification | Balance Sheet | Unrealized Gains/Losses | Key Risk |
|---|---|---|---|
| Trading | Fair value | Income statement (every quarter) | Earnings volatility |
| Available-for-Sale (AFS) | Fair value | Other Comprehensive Income (OCI) | Hidden in equity section |
| Held-to-Maturity (HTM) | Amortized cost | Completely ignored | Invisible losses if forced to sell |
How securities classification drove the SVB collapse
Security-classification accounting was at the center of the Silicon Valley Bank collapse in 2023 — and the details matter. SVB's fire-sale was its AFS book: it sold ~$21B of AFS securities and realized a $1.8B loss. The HTM portfolio's far larger unrealized losses (~$15B, visible only in a fair-value footnote) were never sold — but depositors understood that selling even one HTM bond would 'taint' the whole portfolio and force fair-value recognition, so the footnote alone was enough to start the run.
The hidden losses buried in AFS and HTM
AFS creates a hidden pocket of gains and losses. A company might report steady net income while sitting on $2B of unrealized losses in its AFS portfolio, visible only in the OCI section of shareholders’ equity.
Hidden HTM Loss = Amortized Cost − Fair Value
CECL (ASC 326) requires banks to estimate lifetime expected credit losses at origination — not when losses become probable. During COVID-19, major banks collectively booked over $50B in CECL reserves in a single quarter.
| Feature | Old Model (Incurred Loss) | CECL (Expected Loss) |
|---|---|---|
| When to reserve | When loss is probable | At origination |
| Time horizon | Current period | Lifetime of the asset |
| Impact on banks | Delayed recognition | Front-loaded, cyclical surges |
| Forecasting | Not required | Must use reasonable forecasts |
Compare amortized cost to fair value for HTM bonds
Spotting hidden risk in an HTM portfolio
Why the amortized-cost to fair-value gap matters
How HTM and AFS diverge in a rate shock
Sit with the ideas.
A bank holds a $500M bond portfolio classified as HTM. Due to rising interest rates, the portfolio's fair value has declined to $430M. The bank reports healthy net income and passes its regulatory capital requirements. Is there a hidden risk?