Will Broadcom publicly disclose custom AI silicon wins at a hyperscaler currently using Marvell by December 31, 2026?

The Q4 FY2026 earnings data meaningfully reduces the probability from the prior 38% estimate, but does not eliminate it. The critical distinction is that this market resolves on BROADCOM's disclosures, not Marvell's. Marvell's CEO forcefully dismissing competitive noise and growing sockets to 20+ tells us Marvell is not currently losing programs — but it does not preclude Broadcom from independently winning NEW programs at overlapping hyperscalers. Hyperscalers structurally dual-source by design, and with AI CapEx expanding rapidly, they have both the budget and the strategic incentive to develop parallel supply chains. Broadcom has 3+ earnings calls remaining before year-end 2026 (FY2026 Q2 in June, Q3 in September, Q4 in December) where they could announce new custom silicon wins. Broadcom's $40B+ revenue base and Google TPU track record give them credibility to win at AWS, Microsoft, or Meta. I reduce from 38% to 28%, primarily because: (1) the expanding-pie dynamic means Broadcom can win without displacing Marvell, reducing strategic urgency; (2) CEO's specific mention of analysts retracting notes suggests the competitive rumors were factually incorrect; (3) growing socket count signals deepening customer relationships, not loosening ones.

I weight Broadcom's independent strategic trajectory more heavily than Marvell's earnings signals. The fundamental market structure hasn't changed: there are only two companies that can design custom ASICs at hyperscaler scale, and every major hyperscaler wants at least two vendors for supply resilience. Google already uses Broadcom for TPU — and Google is listed as one of Marvell's custom XPU customers. If Google is already dual-sourcing between Marvell and Broadcom, it's quite plausible that AWS or Microsoft would pursue the same strategy. The fact that Marvell is winning MORE programs (20+ sockets, new Tier 1 XPU) is actually consistent with an expanding market where Broadcom is ALSO winning programs — these are not zero-sum outcomes. The key question is whether Broadcom will PUBLICLY DISCLOSE such wins. Broadcom's CEO Hock Tan tends to be less specific about individual customer wins compared to Marvell's Matt Murphy, which could reduce the disclosure probability even if Broadcom has overlapping engagements. I assign 32% — lower than the prior 38% because Marvell's Q4 data reduces the likelihood that existing programs are being lost, but still meaningful because new Broadcom programs at overlapping customers remain plausible and Broadcom has multiple disclosure opportunities remaining.

The earnings update provides the strongest evidence yet that Marvell's customer relationships are deepening, not eroding. Let me enumerate what would need to happen for YES resolution: (1) Broadcom would need to have active custom AI silicon programs at AWS, Google, Microsoft, or Meta; (2) Broadcom would need to publicly confirm this in earnings calls, filings, or press releases by December 31, 2026; (3) These would need to be at hyperscalers 'currently using Marvell' for custom XPU. Google already uses both — so the question is really about NEW Broadcom wins at AWS, Microsoft, or Meta specifically. AWS just affirmed its Marvell partnership and has a strategic warrant structure in place. Microsoft could be a target for Broadcom, but no public signals exist. Meta is possible but they also have internal MTIA silicon. The timeline is getting shorter — we're now in March 2026, and Broadcom's remaining 2026 earnings calls may not cover programs that are in early development stages. Custom silicon co-development takes 2-3 years, so any program Broadcom would announce in 2026 would have been started in 2023-2024. The absence of any signals through Q4 FY2026 is incrementally informative. I assign 25%.

The updated evidence package shifts the probability meaningfully downward but not dramatically. Here is my framework: Base rate for Broadcom disclosure = prior 38%. Adjustment factors: (1) Marvell CEO's forceful dismissal with analyst retractions: -5pp (suggests the specific competitive overlap rumors were factually wrong, but doesn't address unreported engagements); (2) Socket count growth 18+ to 20+: -2pp (shows Marvell gaining, not losing, but Broadcom can also be gaining at the same customers); (3) New Tier 1 XPU program confirmed: -1pp (marginal — could even be at a customer Broadcom is also pursuing); (4) Supply chain secured for multi-year: -2pp (implies committed customer relationships); (5) No Broadcom disclosure yet as of March 2026: -3pp (each passing quarter without disclosure is incrementally informative). Net adjustment: approximately -13pp from a 38% starting point, but I apply some regression toward the structural prior (dual-sourcing is standard, Broadcom has capability and incentive). Final: 30%.

I want to focus on the disclosure mechanism specifically. For this market to resolve YES, Broadcom must PUBLICLY confirm custom AI silicon engagements at Marvell's customers. Broadcom's recent earnings calls have been focused on: VMware integration, networking switching dominance, and their existing custom silicon relationships (primarily Google TPU, and potentially others they haven't named). Hock Tan's communication style is notably different from Matt Murphy's — Tan speaks in broader revenue categories ($15.6B AI revenue in FY2025) without naming specific customers or socket counts. This means that even if Broadcom has begun co-development with, say, AWS for a custom accelerator, they may not publicly name AWS as a customer in an earnings call. The resolution criteria requires 'publicly confirms new custom AI silicon engagements... at hyperscaler customers that Marvell currently serves.' This is a specific disclosure test, and Broadcom's disclosure habits work against YES resolution. Meanwhile, the Q4 MRVL data showing growing sockets, new programs, and CEO dismissal of competitive noise all reduce the probability that there ARE overlapping engagements to disclose. Combined with the shorter remaining timeline (9 months), I set this at 26%.

I want to steelman the YES case because I think the consensus may be anchoring too heavily on Marvell's positive earnings narrative. Consider: (1) Broadcom's custom AI silicon revenue is growing explosively — they guided to $60-90B AI serviceable addressable market. They cannot achieve this by serving only Google. They MUST be expanding to new hyperscaler customers. (2) The resolution window extends through December 31, 2026, which includes Broadcom's FY2026 Q3 and Q4 earnings calls. If Broadcom has been co-developing custom silicon with AWS or Microsoft since 2024, a program could reach the announcement stage by H2 2026. (3) Marvell's CEO dismissing competitive noise could be genuinely accurate about EXISTING programs while being uninformed about new Broadcom programs at his customers that haven't been publicly discussed. CEOs often learn about competitor wins at their customers after the fact. (4) The 'analysts retracting notes' could refer to specific inaccurate reports about Marvell LOSING programs, while being silent on the distinct question of Broadcom WINNING parallel programs. I assign 33% — reflecting genuine uncertainty about Broadcom's expanding customer footprint even as Marvell's position strengthens.

The Q4 update meaningfully de-risks but doesn't eliminate the Broadcom overlap scenario. Key: Marvell growing sockets to 20+ and hitting $1.5B custom target shows strength, but this market is about Broadcom's disclosures, not Marvell's performance. Broadcom has 9 months of potential disclosure windows remaining. The dual-sourcing structural norm means overlapping engagements are plausible even when both companies are winning. CEO's forceful dismissal reduces probability from prior 38% by roughly 10pp. Set at 27%.

Taking a more aggressive downward revision. The combination of: (1) growing socket count, (2) new Tier 1 program, (3) CEO's explicit mention of analysts retracting competitive overlap notes, (4) secured multi-year supply chain, and (5) still no Broadcom disclosure after 14+ months of this monitoring trigger being active — all point to meaningfully lower probability. The 2-3 year co-development cycle is key: if Broadcom hasn't started programs at Marvell's customers by now, they won't have anything to disclose by year-end 2026. The structural dual-sourcing argument has limits — it takes years to establish a second vendor for custom silicon, unlike commodity products. I set this at 22%.

Maintaining a relatively higher estimate because the YES scenario doesn't require Marvell to be doing poorly. In an expanding AI CapEx environment, both Broadcom and Marvell can simultaneously win at the same hyperscaler for different product generations or different chip categories. AWS could use Marvell for one accelerator and Broadcom for another. The fact that only two companies can do this work makes it INEVITABLE that they will compete for the same customers. Broadcom's massive revenue base and Google TPU pedigree gives them the credibility to win anywhere. However, the disclosure element adds friction — Broadcom may prefer not to name customers. Net: 30%.