Treasury, IRS provide guidance on the new deduction for car loan interest under the One, Big, Beautiful Bill

The U.S. Treasury and IRS issued proposed regulations implementing a new deduction for interest paid on vehicle loans incurred after Dec. 31, 2024, for new, made-in-America personal-use vehicles, with a clarified $10,000 annual deduction limit and applicability to both standard and itemizing taxpayers. The guidance defines eligible vehicles (including U.S. final assembly), loan qualification and deductible interest, and requires lenders to file information returns reporting interest to enable taxpayers to claim the benefit; public comments are invited through Feb. 2, 2026.

Analysis

Market structure: The deduction for interest on car loans (vehicles bought after 12/31/2024, $10k annual cap) favors manufacturers and lenders tied to US final assembly — expect a modest demand tilt toward Ford (F), GM (GM) and Tesla (TSLA) models built in‑country. Auto retailers, captive financiers and ABS originators should see higher originations and longer tenors; dealers with high-margin new-vehicle mix could gain pricing power over trade-ins and used-vehicle channels. Incremental unit demand is likely modest — estimate +1–3% annual new‑vehicle sales concentrated in higher-ticket EVs/luxury models where interest expense is large enough to matter.

Risk assessment: Near-term tail risk includes regulatory re‑interpretation of “final assembly” that could exclude key models or invalidate demand assumptions; worst‑case could shift production patterns and create stranded inventory capex over 12–36 months. Operational risks: lenders face immediate reporting/compliance costs (forms, systems) that compress near‑term margins; macro risk: if rates fall materially the relative value of the deduction shrinks. Catalysts to monitor: IRS final regs (due by 2/2/2026 comment deadline), OEM public statements on production sourcing, and Q1 retail auto sales data for outsized share shifts.

Trade implications: Favor equities of US‑assembled OEMs and captive lenders (ALLY) and senior auto ABS; implement via defined‑risk option spreads to cap downside while capturing 3–12 month demand re‑rating. Use pair trades to express domestic vs import exposure (long F/GM, short TM/HMC) and overweight financials with above‑market auto exposure in bank ETF XLF and standalone ALLY. Fixed income: prefer A/AAA senior tranches of new‑issue prime auto ABS (target 75–150bp pick up vs comparable Treasuries) to capture spread tightening and lower delinquencies.

Contrarian angle: The market may over‑index to OEM upside and underweight lenders/ABS; the real value lies in credit improvement for securitized paper and captive finance margins rather than headline unit growth. Conversely, consensus may also overstate consumer uptake — the deduction benefits interest, not principal, so price‑sensitive buyers or cash purchasers see little change, implying upside concentrated in higher‑priced EVs and premium trims. Watch for unintended consequences: OEMs could respond with rebate/finance tweaks that nullify the tax incentive, compressing expected winner returns within 3–9 months.

Key Decisions for Investors

• Establish a 2–3% long position in Ford (F) and GM (GM) combined (equal weight) via 6–12 month call spreads targeting 35–45 delta to capture a 3–12 month demand re‑rating tied to US assembly exposure.
• Initiate a 1–1.5% long position in Ally Financial (ALLY) equity to play higher origination volumes and lower auto‑loan delinquencies over 3–6 months; size via stock or 3‑month bullish call ladder to limit downside.
• Enter a pair trade: long Ford (F) 2% / short Toyota (TM) 1.5% to express domestic assembly advantage; hold 3–12 months and rebalance if final IRS regs (by 2/2/2026) change assembly definitions.
• Allocate 3–5% of fixed‑income allocation to senior tranches of newly issued prime auto‑loan ABS (A/AAA), targeting 75–150bp spread over Treasuries and preferring pools of vehicles with post‑2024 US final assembly; execute on new issues within 0–6 months.
• Delay scaling beyond pilot sizes until final IRS rules are published (post 2/2/2026 comment deadline); if final guidance widens 'made‑in‑America' scope, increase exposure to US OEMs and captive finance by an additional 2–4%.