OSB GROUP PLC Interim Report for the six months ended 30 June 2026

OSB Group reported H1 2026 profit before tax of £187.2m, down 3% year-on-year, with net interest margin falling 7 bps to 223 bps as more costly spreads to SONIA from new retail funding offset back-book dynamics. Loan loss ratio rose to 12 bps (from 2 bps), while administrative expenses increased 4% to £136.5m and RoTE declined to 13.3%. Management kept 2026 guidance broadly intact but cut clarity around returns: it now expects 2026 net interest margin of 215–220 bps and RoTE around 12.5% (excluding incoming CEO costs), with a potential modest drag on its 2027 mid-teens RoTE aspiration if funding costs remain elevated. The company declared an interim dividend of 11.8 pence (+5%) and reported £69.5m of buybacks completed under a £100m programme.

Analysis

This is a margin-cycle warning disguised as a resilient update. Credit is not the problem; the real issue is that OSB’s earnings power is unusually exposed to retail funding competition, so the stock should trade more like a spread business than a pure lender until deposit beta normalizes. The second-order loser is the broader UK specialist-lender cohort: when rates stay elevated, firms without sticky transactional deposits are forced to choose between share and spread, and OSB is signaling it will defend neither aggressively enough to protect prior ROE.

The balance sheet still buys time. Capital return capacity and ongoing securitization access reduce near-term solvency risk, and the book-value story is intact, which should limit downside versus a true credit turn. But if funding pressure persists into the next 2-3 quarters, the market will start underwriting a lower terminal ROE and a slower rerating path; that matters more than the current period’s modest loan growth because the multiple has been supported by a mid-teens aspiration.

Contrarian view: consensus may be overreacting to the margin cut while underweighting execution on the platform migration and MREL roll-off, both of which could mechanically lift ROE in 2028-29. The thesis is falsified if management can hold 2026 NIM near the upper end of guidance and avoid any 2027 aspiration haircut at year-end. Conversely, if deposit pricing stays sticky through autumn refinancing season, the stock should remain capped until the rate cycle turns.

Key Decisions for Investors

• Short OSB.L on any post-print strength for a 1-3 month trade; this is a multiple compression call on lower terminal ROE, not a credit short. Invalidate if management raises 2026 NIM guidance or explicitly reaffirms 2027 mid-teens ROE without caveats.
• Pair trade: long LLOY.L or NWG.L vs short OSB.L over the next 2-3 months. Thesis: deposit-franchise banks should outperform specialist lenders when retail funding remains expensive. Cover if BoE easing or mortgage-swap relief narrows the funding gap materially.
• Buy a 3-6 month OSB put spread if listed options/liquidity are adequate; target downside from guidance-risk rather than default risk. Best entry is after the initial volume washout, when implied vol is still below event risk.
• Watch for a FY26 pre-close update on 2027 ROE; if management trims the mid-teens aspiration, add to shorts in specialist lenders with similar deposit beta. If that update is clean, reduce bearish exposure because the market may have over-discounted the reset.
• Use UK specialist-lender peers as a basket alert, not a blanket short. Any lender with high retail-funding reliance and limited transactional deposits is vulnerable to the same mechanism; relative winners are deposit-rich retail banks and lower beta funding models.