Munich Re’s HSB to buy At-Bay four years after backing its $1.35bn round

Munich Re Group (XETR: MUV2) has agreed to acquire San Francisco-based cyber insurtech At-Bay Inc. at an enterprise value of $575 million, in a transaction the German reinsurer expects to close in the first quarter of 2027 subject to customary regulatory approvals. Munich Re said At-Bay would sit inside Hartford Steam Boiler (HSB), the specialty insurance arm that has been At-Bay’s lead reinsurer and largest capital provider since 2022. The agreed price represents a decline of roughly 57 percent from At-Bay’s $1.35 billion post-money valuation set at its 2021 Series D round, and follows Munich Re’s earlier ERGO-led acquisition of Next Insurance for approximately $2.6 billion completed in March 2025. Munich Re shares traded around €519 in Frankfurt on Aug 19, easing about 0.9 percent on the announcement day. The central tension for the market is whether the deal represents disciplined bottom-of-cycle entry into a strategic specialty line, or whether Munich Re is paying a full multiple for an underwriting book that recorded a small loss in 2025.

What does Munich Re’s agreed $575m At-Bay acquisition change for its US cyber franchise?

The transaction converts a four-year capacity and reinsurance relationship into direct ownership of At-Bay’s insurance operations, its captive, its security-services business, and the technology platform that connects the two. At-Bay reported gross written premiums of $278 million and cyber fee-service revenue of $23 million for the year ended Dec 31, 2025, and Munich Re described At-Bay as a top-10 US cyber insurer serving approximately 40,000 small and medium-sized enterprises. At-Bay employs roughly 280 staff across the United States and Israel. Chief executive Rotem Iram told trade publication The Insurer in May 2025 that At-Bay was, by his estimate, the seventh-largest US cyber insurer and the largest writer of cyber insurance through the wholesale channel. For Munich Re, the acquisition consolidates a cyber franchise that generated $1.7 billion in premiums during 2025, split evenly between primary insurance and reinsurance, and gives HSB direct control over the underwriting decisions that its reinsurance treaties had previously supported at arm’s length.

Why did At-Bay’s valuation reset from $1.35bn in 2021 to $575m under Munich Re?

At-Bay closed a $185 million Series D funding round in July 2021 co-led by Icon Ventures and Lightspeed Venture Partners, with participation from Khosla Ventures, M12, Acrew Capital, Qumra Capital, entrepreneur Shlomo Kramer, Glilot Capital, and the HSB fund of Munich Re Ventures. That round brought total disclosed funding to $272 million and set a post-money valuation of $1.35 billion. Total capital raised across the company’s life reached approximately $276 million to $296 million, depending on the source. The agreed enterprise value of $575 million therefore sits 57 percent below the 2021 mark and represents a multiple of roughly 2 times 2025 gross written premiums. That multiple sits within the broad range at which cyber specialty books have traded in recent private-market transactions, and it reflects the wider reset in insurtech valuations since the 2021 venture peak, when several publicly listed insurtechs were rerated sharply lower on questions about loss ratios, expense structures, and the path to underwriting profitability. Whether the reset reflects a distressed sale, a negotiated fair-market outcome between long-standing partners, or a discount for the operating losses recorded during 2025 is not disclosed in the transaction announcement.

How does the At-Bay deal fit inside HSB’s role as Munich Re’s specialty cyber arm?

HSB, formally Hartford Steam Boiler, is Munich Re’s technology-focused and cyber-focused specialty insurance business, historically anchored in equipment breakdown and industrial machinery inspection. Since At-Bay’s founding in 2016, HSB has been its principal reinsurance partner, and Munich Re said HSB has been the largest capital provider and lead reinsurer since 2022. Mike Kerner, member of Munich Re’s board of management, said in the deal announcement that At-Bay’s capabilities were an essential component of the group’s future cyber offering and that management expected the business to become a strong earnings-growth driver over time. The rationale is a familiar reinsurer-to-primary integration play: HSB captures the underwriting economics it had previously shared with At-Bay as an independent MGA, gains ownership of the data flows and security telemetry that inform pricing, and consolidates client relationships across the specialty portfolio. The corollary is that Munich Re now takes execution risk on integrating a Silicon Valley-style engineering culture into a legacy specialty insurance operation, an integration profile similar to the one the group inherited when ERGO absorbed Next Insurance earlier in 2025.

What does At-Bay’s 2025 underwriting loss say about the economics HSB is buying into?

At-Bay Specialty Insurance Company, the group’s carrier entity, reported $269.2 million in gross written premiums and $39.6 million in net written premiums for 2025, according to statutory disclosures reviewed by trade publication Coverager. The carrier recorded an underwriting loss of $6.8 million and a net loss of $615,000 for the year, ending 2025 with $228 million in assets and $100.2 million in policyholder surplus. Those figures do not include At-Bay’s separate cyber fee-service revenue of $23 million, and much of the group’s gross premium production is ceded to reinsurers, HSB included, which limits net retention on the carrier balance sheet. The read for Munich Re is therefore not simply a top-line multiple. Ownership brings the ability to reset ceding commissions, restructure reinsurance internally, retain a larger share of the fee-service margin, and apply HSB’s expense base against a growing specialty book. The read for market observers is that the acquired operating book was not yet self-sustaining at the carrier level in the year immediately preceding the transaction, and the earnings-growth thesis Kerner outlined depends on Munich Re reversing that trajectory once the business is inside the group.

How does the InsurSec platform reshape underwriting inputs for HSB and Munich Re?

At-Bay operates what it calls the InsurSec model, combining cyber insurance with a continuous security-monitoring platform that scans policyholders’ external attack surface, identifies vulnerabilities, and provides managed detection and response services during the policy term. The company reported that the platform addresses risk factors associated with 86 percent of customer claims, which Munich Re highlighted as a differentiator relative to standalone cyber cover. Iram framed the security business in the May 2025 Insurer interview as generating tens of millions of dollars in service revenue and creating a path to grow the insurance book without compromising underwriting discipline. For HSB, the operational value is real-time telemetry across a portfolio of small and medium-sized enterprises, feeding underwriting models that have historically depended on point-in-time application data and claims lag. That data asset is difficult to replicate without either building an in-house security operations centre or acquiring one, and it is the primary reason competing cyber acquisitions have gravitated toward specialised MGAs rather than pure carrier books. Whether the platform’s marginal underwriting benefit scales cleanly across HSB’s existing specialty book, or whether it remains a stand-alone At-Bay capability, is the operational question that will define the integration.

Where does the At-Bay agreement sit against Travelers, Zurich and the wider cyber MGA reset?

The Munich Re transaction is the third significant strategic move by a large carrier or reinsurer into a cyber MGA in roughly two years. Travelers acquired cyber MGA Corvus in 2024. Zurich made a $60 million Series C investment in Cowbell, which trade coverage has interpreted as a positioning move ahead of a potential fuller acquisition, and Zurich also closed its acquisition of Beazley in a separate specialty-market consolidation. Munich Re itself demonstrated the same insurtech-at-scale appetite with the ERGO acquisition of Next Insurance for approximately $2.6 billion earlier in 2025. The pattern suggests that cyber MGAs are no longer being valued as standalone growth stories but as strategic assets whose data platforms, distribution relationships, and specialised underwriting talent are worth more inside a large-balance-sheet carrier than as independent capital-raising entities. For At-Bay specifically, the sale to Munich Re also resolves a strategic question raised implicitly in Iram’s May 2025 comments, when he said the company was well capitalised, had no immediate need to return to investors, and would consider acquisitions only on its own terms. Fifteen months later, the company has been sold, at less than half its last private-market mark, to a partner it has worked with since 2022.

What signal does Munich Re’s cyber redeployment send about the reinsurance softening cycle?

Munich Re’s chief cyber underwriter Jürgen Reinhart estimated the global cyber insurance market at approximately $16 billion during July 2026 industry commentary. Munich Re’s own $1.7 billion in 2025 cyber premiums implies a market share of roughly 10 percent on that estimate, placing the group among the leading global writers by volume. Set against the broader reinsurance backdrop, cyber redeployment carries strategic weight. Trade coverage during the first half of 2026 reported material rate declines across loss-free catastrophe reinsurance layers, driven by abundant traditional and alternative capital. Munich Re reported first-half 2026 net income of €3.9 billion and a return on equity of 23 percent, but management also signalled a lowered guidance line during the second quarter as pricing pressure in cat reinsurance began to bite. Against that backdrop, moving capital toward cyber, where demand growth outpaces mature property-catastrophe lines and where technology-driven underwriting can create durable differentiation, is a defensible portfolio-mix decision. The market will judge whether Munich Re executed the redeployment near the bottom of the cyber cycle, which softened materially during 2024 and 2025 after the ransomware-driven hard market of 2021 and 2022, or whether the cycle continues to soften into 2027 and compresses the return profile Munich Re is underwriting today.

Which regulatory milestones and forward proof points still stand between agreement and Q1 2027 close?

The transaction remains subject to customary closing conditions including regulatory approvals, and Munich Re has guided completion during the first quarter of 2027. That timeline implies competition and insurance-regulatory review in the United States, where At-Bay writes on its own paper through At-Bay Specialty Insurance Company and previously issued policies through third-party carriers. Israeli regulatory considerations may also arise given At-Bay’s engineering base in the country. Between agreement and close, the market’s forward proof points are the group’s Q3 2026 results release scheduled for Nov 11, 2026, at which Munich Re will provide the first quantitative colour on the transaction’s expected earnings contribution and any commentary on cyber cycle conditions; disclosure of any material change in At-Bay’s underwriting book between year-end 2025 and completion; and the granularity Munich Re provides on how HSB will structure the reinsurance flows now that the ceding relationship becomes intragroup. After close, the primary test will be whether At-Bay’s specialty carrier moves from a small underwriting loss in 2025 to sustained underwriting profitability under HSB governance, and whether the InsurSec platform’s data feeds measurably improve loss ratios on the broader HSB cyber book.

What should the market watch as Munich Re moves the At-Bay deal toward its Q1 2027 close?

• Munich Re Group (XETR: MUV2) has agreed to acquire At-Bay Inc. at an enterprise value of $575 million, with completion expected in the first quarter of 2027 subject to regulatory approvals.
• The agreed price represents a decline of roughly 57 percent from At-Bay’s $1.35 billion post-money valuation set at its 2021 Series D funding round and a multiple of approximately 2 times 2025 gross written premiums of $278 million.
• At-Bay will sit inside Hartford Steam Boiler, the specialty insurance arm that has been At-Bay’s lead reinsurer and largest capital provider since 2022, converting a longstanding capacity relationship into direct ownership.
• At-Bay Specialty Insurance Company reported $269.2 million in gross written premiums and $39.6 million in net written premiums for 2025, with an underwriting loss of $6.8 million and a net loss of $615,000 at the carrier level.
• The InsurSec platform, which combines cyber cover with continuous security monitoring for approximately 40,000 US small and medium-sized enterprise policyholders, brings real-time underwriting telemetry that has been difficult for legacy specialty carriers to replicate organically.
• The deal continues a consolidation wave that includes Travelers’ 2024 acquisition of Corvus, Zurich’s Series C investment in Cowbell and its acquisition of Beazley, and ERGO’s approximately $2.6 billion acquisition of Next Insurance completed in March 2025.
• Munich Re generated $1.7 billion in cyber insurance premiums during 2025, split evenly between primary insurance and reinsurance, giving the group roughly 10 percent share of the approximately $16 billion global cyber market estimated by chief cyber underwriter Jürgen Reinhart in July 2026.
• Redeployment toward cyber comes as pricing in loss-free catastrophe reinsurance softened materially through the first half of 2026, testing whether Munich Re is entering cyber near a cyclical low or ahead of continued softening into 2027.
• Munich Re shares traded around €519 in Frankfurt on Aug 19, easing about 0.9 percent on the announcement day, against first-half 2026 group net income of €3.9 billion and a return on equity of 23 percent.
• Forward proof points include the Nov 11, 2026 Q3 results release for initial earnings-contribution guidance, regulatory clearances in the United States and Israel between announcement and close, and post-close evidence that At-Bay’s carrier can move from underwriting loss to sustained profitability under HSB governance.