Most treasury teams treat SOFR basis risk as solved because the hard fallback deadline passed—but it isn’t solved for illiquid tenors, bilateral contracts, and legacy hedging relationships where cash flows don’t align across currencies and maturities. The unresolved problems are deeply technical, cross-functionally opaque, and create hidden P&L drag that compliance and risk haven’t fully mapped.
The Transition Is Legally Complete. The Risk Work Isn’t.
The U.S. Federal Reserve set a hard deadline: June 30, 2023, after which new U.S. dollar contracts could no longer reference LIBOR. That date arrived and passed. Thousands of firms declared SOFR transition “complete” in regulatory filings, board decks, and investor calls. The press releases rolled. The consultants were paid. The working groups disbanded.
But for treasury teams managing multi-currency portfolios, bilateral swap agreements that predate the transition, and hedging relationships in illiquid tenors—the real work began on July 1, 2023, and it’s still unfinished. Not because of regulatory foot-dragging or market infrastructure gaps. Because basis risk—the risk that SOFR-indexed instruments don’t behave exactly like their LIBOR predecessors when markets stress—hasn’t been fully priced, hedged, or stress-tested in the way a competent CFO should demand.
The gap between “we’ve complied with the fallback amendment rules” and “we’ve genuinely hedged our basis risk across all material cash flows” is precisely where treasury teams are bleeding P&L today.
What the Regulators Actually Required—and What They Didn’t
The Financial Conduct Authority (FCA), the Office of the Comptroller of the Currency (OCC), and the Bank for International Settlements (BIS) all issued guidance requiring firms to transition to SOFR by June 30, 2023, or operate under formal fallback language in contracts. That was a gate. It wasn’t a solution.
Fallback amendments are legally binding instructions: if LIBOR ceases to exist (or becomes unrepresentative), the contract converts to SOFR plus a fixed spread—the “spread adjustment.” That adjustment is meant to make the SOFR contract economically equivalent to the original LIBOR bargain. In theory, it’s a clean swap. In practice, it compresses months of dynamic price discovery into a single number calculated on a specific date, under specific market conditions, for specific tenors only.
For the most liquid LIBOR tenors—3-month and 6-month USD LIBOR, which accounted for the vast majority of cleared derivative contracts—the regulator-endorsed spread adjustments worked reasonably well. Those tenors had deep SOFR futures markets, years of historical basis data, and active dealer participation in the transition. But for 12-month tenors, for less-liquid currencies (sterling forwards, euro forwards), and for bilateral (non-cleared) contracts that don’t trade in active markets, the spread adjustment is a blunt instrument applied to a sharp risk.
The regulators didn’t require treasury teams to measure basis risk after transition. They required compliance with fallback mechanics. That’s two different things.
The Unresolved Basis Risk Problems Treasury Teams Face Today
1. Tenor Basis Mismatch in Illiquid Markets
A regional bank’s treasury team hedges a 5-year fixed-rate bond issuance using a 5-year LIBOR swap. When the fallback triggers, that swap becomes a 5-year SOFR swap locked at the spread adjustment calculated on the effective date. But the bank’s liability-side funding profile depends on rolling 3-month LIBOR borrowing costs. When the bank refinances quarterly, it’s benchmarked to 3-month SOFR rates, which don’t move in lockstep with the 5-year SOFR rate embedded in the hedging swap.
That tenor basis—the difference between the 3-month and 5-year SOFR curve movements—creates dynamic P&L volatility. In a steepening curve environment, the bank’s funding costs (tied to 3-month SOFR) rise faster than the hedging swap revalues (locked at 5-year SOFR). The hedge no longer works as intended. Regulators didn’t require stress tests for tenor basis. So most treasury teams don’t have them.
2. Bilateral Contract Opacity
Not all derivatives are cleared through LCH, CME, or Eurex. Smaller institutions, regional banks, and specialty finance firms hold material bilateral (non-cleared) swap books with correspondent banks, asset managers, and insurance companies. Those contracts were supposed to be converted under the ISDA fallback protocol or manually renegotiated. But manual renegotiation creates a two-tier market: some bilateral swaps were amended, some weren’t, and some exist in contractual gray zones where the fallback language is ambiguous.
In illiquid bilateral swap books—say, a bank’s swap with a pension fund or a regional credit union’s hedge with a larger correspondent—the spread adjustment calculation becomes a negotiation, not a market fact. One bank calculates the spread using Bloomberg’s recommended methodology; the other uses ICE’s. One firm uses historical medians; the other uses forward-looking regression. The economic outcome can differ by basis points, which for large notional values compounds into material P&L.
Treasury teams have contact lists for these counterparties, but few have systematic audit trails proving that every bilateral contract was properly amended and that both sides agree on the spread adjustment used.
3. Multi-Currency Basis Risk and Hedge Accounting Complications
A eurozone bank funds itself in euros but pays liabilities in US dollars. It hedges the FX risk using EUR/USD cross-currency swaps. Those swaps benchmark the floating leg to LIBOR. When LIBOR falls away, the cross-currency swap converts to a SOFR benchmark, but the euro leg might remain on EURIBOR (which persists as a working rate). The resulting EUR/SOFR swap behaves differently than the original EUR/LIBOR swap across different market scenarios—particularly when interest rate differentials widen.
Under hedge accounting rules (IFRS 9 or ASC 815), the treasury team must document the hedge relationship and demonstrate that the hedge is effective. A basis change caused by the LIBOR-to-SOFR transition could, in theory, break the documented hedge relationship, forcing the firm to recognize mark-to-market volatility in the income statement rather than deferring it in other comprehensive income. Big banks with hedge accounting infrastructure have managed this. Smaller institutions with simpler finance teams haven’t systematically reviewed it. And none of them have clean audit trails proving effectiveness on both sides of the transition.
4. Daily Compounding vs. Term SOFR Mismatch
The SOFR market fractured into two regimes: compounded SOFR (the default in many cleared contracts and floating-rate notes) and Term SOFR (administered by the CME, with fixed tenors like 3-month and 6-month). Compounded SOFR captures the average cost of overnight funding over a period. Term SOFR is a forward-looking rate published daily for specific maturities, similar to how LIBOR worked.
When an old LIBOR contract fallback to compounded SOFR, the calculation method changes. The economic economics of the swap change. For firms managing both derivative hedges and cash bonds or floating-rate notes (which may reference Term SOFR), the basis between the two SOFR methodologies creates hidden hedge ineffectiveness. This basis has averaged 5–15 basis points historically, but in market stress it widens. Most treasury teams don’t have a view of how their compounded vs. Term SOFR exposures interact under adverse scenarios.
5. Accrued Interest and Reset Date Alignment Issues
In swaps, interest accrues on the floating leg from the last reset date to the calculation date. With LIBOR, that reset was typically 2 business days before the payment date. With SOFR, compounds daily. For contracts where the fallback language didn’t precisely specify new reset dates and day-count conventions, there’s a gap: the accrued interest calculation between the LIBOR regime and the SOFR regime may not reconcile cleanly. Across thousands of contracts, these small gaps compound into a material reconciliation problem.
Few treasury teams have run systematic reconciliation of accrued interest pre- and post-transition. Accounting systems often flag the difference as a one-time P&L hit or a balance sheet adjustment. But proper documentation of basis risk—and proof that the spread adjustment properly compensated for this timing difference—is weak.
What Do Treasury Teams Actually Need to Do?
A competent treasury function should have completed three core work streams by now, and most haven’t fully done any of them:
1. Portfolio-Level Basis Risk Measurement. Map all SOFR-converted contracts (cleared and bilateral) by tenor, currency, and reset date. Calculate the historical basis between each contract’s original LIBOR benchmark and its new SOFR benchmark under normal and stress scenarios. Quantify P&L sensitivity to basis widening. This requires infrastructure most regional treasuries don’t have—either sophisticated quant models or outsourced hedge accounting software. Most treasury teams treat this as a compliance checkbox, not a living risk.
2. Bilateral Contract Audit and Renegotiation. For every non-cleared swap still on the books, confirm in writing with the counterparty that (a) the contract was amended under the ISDA fallback protocol or manually renegotiated, (b) both sides agree on the spread adjustment, and (c) reset date and accrual mechanics are consistent. This is labor-intensive and requires legal review. Most firms have done this inconsistently across their counterparty base. Regional banks and credit unions often have one or two bilateral swaps that haven’t been formally documented as amended, creating latent legal and operational risk.
3. Hedge Accounting Documentation and Rebalancing. If the treasury function uses hedge accounting, it must formally reassess whether the LIBOR-to-SOFR transition breaks the documented hedge relationship. If it does, the firm must either rebalance the hedge (adding or removing notional to correct for basis) or redesignate it (choosing a different accounting treatment). This requires coordination between treasury, finance, and external audit. Most firms have done ad-hoc patches but haven’t formalized a rebalancing calendar or documented the rationale for each rebalancing decision in a way that will satisfy auditors in a future examination.
4. Stress Testing Under Scenarios Where Basis Risk Matters. A rate shock alone doesn’t capture basis risk. You need scenarios where the SOFR-LIBOR basis widens (e.g., stress to financial institutions, liquidity dislocation in money markets) while interest rates move in other directions. Pair that with tenor basis, cross-currency basis, and the specific reset dates in your contract portfolio. Most treasury stress tests don’t layer these together. They run rate shocks or FX shocks in isolation. The firm doesn’t get a realistic view of P&L risk.
None of these are quick fixes. AI-driven predictive liquidity tools can help model tail scenarios and basis sensitivities, but only if the underlying contract data is clean and the basis risk assumptions are explicit. Most treasuries are still entering data manually into legacy spreadsheets.
The Accounting and Audit Trap
Here’s where the problem gets worse. Auditors are now three years into the SOFR era. They’re starting to dig into whether the spread adjustments were correct, whether basis risk was properly hedged, and whether hedge accounting documentation is defensible. When an auditor challenges the treasury team’s methodology for calculating spread adjustments, or questions why a bilateral contract’s amended terms don’t match the ISDA protocol language, it becomes a financial reporting issue, not just a treasury operational issue.
If the adjustment is deemed incorrect or the hedge documentation is weak, the firm might need to restate earnings or disclose a control deficiency in its 10-K or audit report. That’s not abstract risk. It’s hit firms in your peer set, and it’s expensive to remediate.
Basis Risk Across Currencies and Jurisdictions
In major currencies like GBP and EUR, the transition story is different. Sterling LIBOR also had a hard fallback date (January 1, 2022 for most tenors). Most sterling contracts converted to SONIA (the UK’s risk-free rate). But the SONIA spread adjustment was calculated differently from the USD LIBOR-to-SOFR spread, using different methodologies and different dates. A multinational bank with both USD and GBP exposures now has two different basis risks operating on two different timescales.
Euro LIBOR had even more fragmentation. Some euro contracts fell back to EURIBOR (which continued to exist and is regulated under a new methodology). Others converted to €STR (the ECB’s risk-free rate). The resulting portfolio has both EURIBOR-benchmarked and €STR-benchmarked derivatives operating in tandem, with different spread adjustments and reset mechanics. Treasury teams managing euro exposures carry compounded basis risk they often can’t easily hedge because the €STR derivatives market for certain tenors is still illiquid.
Cross-currency treasury teams need to model basis risk for each currency pair separately, then aggregate the risks. Most haven’t done that work.
The Forgotten: Illiquid Tenors and Emerging Market Currencies
USD LIBOR 3-month and 6-month accounted for roughly 95% of the LIBOR derivative market. The transition for those tenors went smoothly because there was massive market liquidity and regulatory focus. But many smaller institutions had exposure to 1-month, 12-month, or non-standard tenor LIBOR swaps. Those tenors had wider, less liquid spread adjustments calculated with fewer market transactions supporting them. A 1-month LIBOR swap, for example, had very few reference transactions when the spread adjustment was set. The resulting SOFR spread may not have reflected the true economic value of the original LIBOR contract.
In emerging market currencies and offshore branches of international banks, the fallback work was slower and less uniform. Some of these contracts are still operating under LIBOR-benchmark terms awaiting eventual conversion or bilateral renegotiation. That’s tail risk: if those contracts suddenly convert, the spread adjustment will be calculated retroactively, creating a step change in valuation that wasn’t anticipated.
Why Compliance and Risk Functions Have Missed This
The SOFR transition was historically a treasury operations problem. Risk and compliance functions were asked: “Are all contracts properly amended? Is fallback language in place? Have spread adjustments been calculated?” Once the answer was yes for >99% of contracts, the project was marked complete. Risk and compliance handed it back to treasury and moved on to the next regulatory project.
But basis risk—whether spreads were correct, whether hedges are still effective, whether P&L volatility from basis changes is properly predicted and disclosed—that’s a risk and finance problem, not just a treasury operations problem. It requires stress testing, hedge accounting revalidation, and multi-dimensional sensitivity analysis. It doesn’t fit neatly into a compliance checklist.
Because it fell between departments, it’s gone largely unmeasured. Now treasury teams are living with the consequences.
Practical Starting Points for Treasury Teams Today
If you’re a treasury manager or CFO reading this, the rework is overdue.
Start with data hygiene. Export all derivatives from your systems by reference rate (SOFR, SONIA, €STR, EURIBOR). Flag which ones were amended, when, and by what methodology (ISDA protocol or bilateral). Identify any contracts for which you don’t have written confirmation of the amendment from the counterparty. That’s your audit priority.
Map basis sensitivities. For the largest notional exposures, calculate what happens to P&L if the SOFR-LIBOR basis widens by 10, 25, or 50 basis points. Do this by tenor and by currency pair. That’s your hedge sizing problem.
Stress hedge accounting. If you use hedge accounting, revisit your documentation for the largest hedges. Ask your auditors whether they expect the LIBOR-to-SOFR transition to create any hedge ineffectiveness you haven’t yet recognized. Get that question answered before your next audit cycle, not during it.
Establish a monitoring calendar. Assign someone to review SOFR-LIBOR basis movements monthly. Track which of your exposures have basis risk and how it’s moving. This becomes part of your monthly treasury reporting.
Modern liquidity and hedging platforms can automate much of this work, but only if you’ve first clarified the data and the methodology.
What the Best-in-Class Treasuries Are Doing
The largest global banks have built dedicated basis risk analytics teams that report to both the chief risk officer and the chief financial officer. They model basis risk as part of the normal risk framework—not as a one-time post-transition validation. Smaller banks that want to compete have started outsourcing hedge accounting and basis risk monitoring to specialized vendors. But the vast majority of regional and mid-market banks haven’t invested in either.
That asymmetry is the risk. In the next rate shock or market stress, the firms with clean basis risk documentation and systematic hedging will recover faster and with fewer surprises. The others will spend weeks in crisis mode trying to figure out why their hedge didn’t work as expected.
Where Basis Risk Still Matters in Your Daily Workflow
Basis risk doesn’t announce itself. It accumulates in quiet moments between positions.
When you rebalance a hedge (adding or removing notional), are you accounting for the spread adjustment that was locked in at transition? Probably not—most treasury systems calculate rebalancing notional based on current market values, not the historical transition spread.
When you fund a new issuance and layering in a hedge, are you calculating the cost assuming the SOFR hedge will match the LIBOR funding cost you’re replacing? Not cleanly—because the basis changes dynamically.
When an auditor asks you to show how you measured hedge effectiveness, can you show basis risk as part of your effectiveness calculation? Probably not systematically—which is why auditors keep asking.
Each of these is a small problem until they compound into a material P&L surprise or a control deficiency your auditor can’t ignore.
The Algoy Perspective
The treasury community—and regulators—made a strategic error in treating the SOFR transition as a “go/no-go” compliance project instead of a multi-year basis risk management initiative. The hard fallback deadline created the illusion that June 30, 2023, was the end. It was actually the beginning.
Regulatory guidance required amendments and fallback language. It didn’t require proof that the economic outcome was correct. That gap is where basis risk lives today. Treasury teams and their finance partners need to reframe this work not as “finishing the transition” but as “measuring and hedging the transition’s residual P&L impact.” That framing changes the priority, the resources allocated, and the accountability structure.
For mid-market and regional institutions, this is a competitive liability. Your larger peers have basis risk analytics. You don’t—yet. But the work is scoped and finite if you start now, before the next market stress makes it urgent and expensive.
Is Your Firm’s SOFR Transition Truly Complete, or Just Compliant?
Compliance means your contracts have fallback language and spread adjustments are documented. Completion means you’ve measured whether those spread adjustments properly hedged your basis risk, you’ve stress-tested the impact of basis widening on your P&L, and you’ve rebalanced your hedges where necessary. Most firms are compliant. Very few are complete. The basis risk lives in that gap.
Frequently Asked Questions
What is SOFR basis risk?
SOFR basis risk is the risk that SOFR-indexed instruments do not behave exactly like their LIBOR predecessors when markets stress. This can lead to P&L drag if not properly managed.
When was the deadline for the SOFR transition?
The U.S. Federal Reserve set a hard deadline of June 30, 2023, after which new U.S. dollar contracts could no longer reference LIBOR.
Did regulators require firms to measure basis risk after the transition?
No, regulators primarily required compliance with fallback mechanics, meaning contracts had to transition to SOFR or operate under formal fallback language. They did not explicitly require treasury teams to measure basis risk after the transition.
What is the difference between compounded SOFR and Term SOFR?
Compounded SOFR captures the average cost of overnight funding over a period and is the default in many cleared contracts. Term SOFR is a forward-looking rate published daily for specific maturities, similar to how LIBOR worked.
What should treasury teams do about unresolved basis risk?
Treasury teams should focus on portfolio-level basis risk measurement, conduct a thorough audit and renegotiation of bilateral contracts, re-evaluate hedge accounting documentation and rebalancing, and perform stress testing under scenarios where basis risk matters.
