Will a second top-20 US card issuer announce migration of debit or credit volume away from Visa or Mastercard to an alternative network by December 31, 2026?

The structural barrier is the dominant fact: Capital One needed $35B to acquire Discover, and no other top-20 US issuer owns a card network. For a second migration announcement by Dec 31 2026, either CCCA must pass or Discover must open to third parties — neither has occurred. The committee's compound scenario (10-15%) requires multiple conditions; within 10.5 months, even if conditions shift, an announcement requires board approval, network negotiation, and public disclosure — a multi-month process. The Black Swan Beacon's 5-10% estimate is likely over a multi-year horizon; compressed to 10.5 months with no current precursor signals, probability is lower.

Searching for upside scenarios: the Durbin Amendment exemption provides ~$1B incentive for three-party debit issuers, and other banks may be conducting internal analysis. However, 'creative paths to similar arrangements' still require a viable network. CCCA legislative timelines are slow, and even if it advances, passage plus implementation plus issuer response within 10.5 months is compressed. The question uses 'top-20' rather than 'top-10', widening the pool, but smaller issuers have less leverage and incentive. The resolution bar is 'commitment or pilot' — higher than mere exploration. Marginally above base because the Durbin incentive is quantifiable and real.

Three specific scenarios could trigger YES: (1) Discover opens as third-party platform — but this cannibalizes Capital One's competitive advantage from the $35B acquisition, making it unlikely without regulatory mandate; (2) CCCA passes creating dual-routing mandate — legislative timelines make 2026 passage very unlikely; (3) An issuer acquires or builds a network — economically prohibitive at $35B+ precedent. The monitoring trigger notes 'no other top-20 issuer has publicly disclosed exploration of alternatives' — starting from zero public activity makes an announcement within 10.5 months extremely unlikely. VAS lock-in at 60% network-integrated creates additional switching costs beyond the payment rail.

The facts are clear: $35B structural barrier with no other issuer owning a network, no public exploration by any top-20 issuer, and the compound contagion scenario at 10-15% requires multiple conditions that haven't materialized. The Black Swan Beacon's 5-10% estimate is over a multi-year horizon; compressing to 10.5 months with zero precursor signals reduces it materially. The only realistic near-term path is Discover opening as a platform, but Capital One has strong competitive incentives to keep it proprietary. CRPO and VAS lock-in make the broader switching cost picture even more daunting.

This is a low-probability event within the specified timeframe. The Moat Mapper assessment is DOMINANT at E3 evidence level with 2/2 committee agreement. Barriers are not just economic but architectural — VAS lock-in at 60% network-integrated means switching costs extend beyond payment rails into fraud detection, tokenization, and analytics services. The 10-15% contagion probability is conditional on CCCA passage AND Capital One credit migration success AND another issuer exploring — the joint probability of all three aligning within 10.5 months is much lower than the individual compound probability. No industry signals of impending exploration exist.

Weighing both sides — against: $35B barrier, no network ownership, no public exploration, VAS lock-in, CCCA not passed, Discover not open. For: $1B Durbin incentive is real, Capital One precedent shifts the Overton window, CCCA could advance in a new Congress. The 'for' factors are all conditional and speculative; the 'against' factors are current, verified, and structural. Generous estimate: ~5% chance Discover opens to a pilot partner, ~30% chance an issuer would announce given that opening — yielding ~1.5% from that path, plus ~3-4% from all other paths combined including surprise regulatory action or an issuer pursuing a novel approach.

The $35B structural barrier is decisive. No other top-20 issuer owns a card network, and no issuer has publicly explored alternatives. The committee's Black Swan Beacon assessed second migration at 5-10% over a longer horizon. Compressed to 10.5 months with no precursor activity, probability is in the 6-8% range. The CCCA and Discover-opening paths are too early-stage to materialize as announcement-level commitments within this window.

Key structural barrier: no alternative network is available to migrate to. Capital One required acquiring Discover for $35B. Discover opening to third parties would cannibalize Capital One's advantage. CCCA has not passed. VAS lock-in at 60% creates additional non-payment switching costs. Zero public exploration signals from any top-20 issuer. Very low probability within 10.5-month window.

Committee base rate of 5-10% for second migration over an unspecified timeframe. Compressed to 10.5 months with no current precursor signals, but the question requires only an announcement (commitment/pilot), not completion. Slight upward adjustment for the possibility of surprise developments (e.g., Discover signals openness to third parties at an investor day, or a large issuer announces a pilot). Multiple structural barriers remain dominant.