Direct answer: SVB failed because it invested short-term deposit funding into long-duration bonds during 2021's zero-rate environment, creating a duration mismatch that became catastrophic when interest rates rose rapidly. By early 2023, SVB's held-to-maturity bond portfolio had unrealized losses of approximately $15 billion against $16 billion in equity. When SVB announced a capital raise to address its balance sheet in March 2023, its concentrated depositor base (tech venture community with strong communication networks) organized a bank run within 48 hours, withdrawing $42 billion in a single day. The FDIC took over on March 10, 2023.
Silicon Valley Bank Investment Autopsy: What Actually Went Wrong?
The investment
Category: Bank Failure / Duration Risk
Era: 2021-2023
Primary failure mechanism: duration mismatch / concentrated depositor base / interest rate risk
Ticker (at time): SIVB
What investors believed
SVB was positioned as the preeminent bank for the technology venture ecosystem, with unmatched industry relationships and a business model that grew deposits naturally as venture capital funding expanded.
What broke
SVB's deposit growth during the 2020-2021 tech boom was deployed into long-duration securities seeking yield in a zero-rate environment. This was an ALM (asset liability management) decision that made sense at zero rates but created extreme interest rate risk. When the Fed raised rates 500 basis points in 12 months, the market value of those securities fell dramatically. AOCI (accumulated other comprehensive income) losses were large but off the income statement under accounting rules. When the losses became public in the capital raise announcement, the concentrated, information-sharing depositor base reacted simultaneously.
Warning signals that were visible
- Duration of held-to-maturity portfolio unusually long relative to peer banks (10+ years average)
- AOCI losses disclosed in quarterly filings but not widely analyzed as a going-concern risk
- Depositor concentration: tech startups with VC backing, who communicate closely, representing 94% of deposits by some analyses
- SVB sold its AFS portfolio at a loss to fund liquidity before the capital raise, signaling balance sheet stress
Transferable lessons
- Duration mismatch is a classical bank risk that receives insufficient attention when interest rates are low
- Concentrated depositor bases that communicate rapidly can exit faster than diversified retail depositor bases
- Held-to-maturity accounting shields income statement from mark-to-market losses but does not eliminate the economic loss
- Unrealized losses in a bank's securities portfolio that approach total equity are a solvency signal, not just an accounting matter
Frequently Asked Questions
Why did SVB hold such long-duration bonds?
SVB's deposit growth accelerated dramatically during 2020 and 2021 as tech venture funding reached record levels. Deposits grew from approximately $62 billion at end-2019 to $189 billion at end-2021. The bank needed to deploy this capital. With short-term rates near zero, short-duration securities offered minimal yield. SVB extended duration to improve net interest margin, investing in 10-year treasury bonds and mortgage-backed securities. This was a common strategy among banks during that period but was extreme in SVB's case. Its chief risk officer had flagged concerns about the investment portfolio's duration. The position was a management decision to accept interest rate risk in exchange for higher current income.
Was SVB actually insolvent when it failed?
This is disputed. SVB had approximately $15-16 billion in unrealized losses on its held-to-maturity portfolio against approximately $16 billion in tangible equity. On a mark-to-market basis, SVB was likely technically insolvent or close to it. However, under banking accounting rules, held-to-maturity securities are not marked to market; if SVB could have held its bonds to maturity, it would have received full face value back. The bank run resolved the question practically: the FDIC took over before any determination of final mark-to-market solvency could be made. The FDIC's subsequent sale of SVB's assets recovered substantially for depositors, suggesting the underlying loan book retained significant value.
What happened to SVB depositors?
The FDIC initially announced that only deposits up to the $250,000 FDIC insurance limit would be guaranteed, but this would have left thousands of tech startups unable to make payroll. The following Sunday, the Treasury, FDIC, and Federal Reserve announced that all deposits at SVB would be made whole, invoking a 'systemic risk exception' that allowed them to protect uninsured depositors without a formal bailout. Silicon Valley Bank's loans and deposits were acquired by First Citizens Bancshares in a transaction with the FDIC in late March 2023. All depositors were fully protected; shareholders and subordinated debtholders received nothing.