Palo Alto Networks tops the network security vendor market by revenue beating rival Cisco, according to Analysys Mason’s cybersecurity vendors’ revenue tracker.

The former’s first-quarter 2020 revenue hit $869 million, driven by 11 acquisitions totaling about $2.5 billion over the last five years. For comparison, Palo Alto Network’s quarterly revenue in Q1 2015 was $234.2 million.

Meanwhile, Cisco’s network security revenue during the first quarter of 2020 reached $776 million, according to Analysys Mason. Fortinet took the No. 3 spot with about $577 million in network security revenue during Q1, and Check Point rounded out the pack with about $487 million during the same time period.

It’s worth noting that while Check Point and Fortinet’s financial years coincide with the calendar year, Cisco’s and Palo Alto Networks’ do not, so Analysys Mason uses February as the starting month of the calendar year for the latter two companies, noted analyst and report author Igor Babic. Additionally, these revenue figures represent total revenue for the three standalone security vendors (Check Point, Fortinet, and Palo Alto Networks), and security-only revenue for Cisco.

When asked if a specific acquisition played a dominant role in Palo Alto Networks’ security growth, Babic said Analysys Mason hasn’t looked at all 11 in enough detail to say which single deal is the most important. “However, the acquisitions of Demisto ($560 million), Twistlock ($410 million) and CloudGenix ($420 million) were larger than the other eight deals and account for around 60% of Palo Alto Networks’ total spend on acquisitions in the last five years,” he added.

The security revenue report also notes that mergers and acquisitions accelerated Cisco’s growth during the second half of 2018 and 2019 — including and “most importantly” Cisco’s $2.35 billion Duo Security acquisition in 2018.

Cisco’s Chief Strategy Officer Anuj Kapur last month hinted that the vendor is looking to make more security acquisitions in the near future.

While Palo Alto Networks topped the revenue ranking, Fortinet’s revenue growth in the second half of 2019 and first quarter of 2020 actually outpaced Palo Alto Networks in large part because of its combined firewall and SD-WAN products, according to Analysys Mason.

Check Point’s revenue grew consistently between 2015 and 2020, but more slowly than the other three vendors. Analysys Mason blames this on its lack of SD-WAN capabilities and no major mergers or acquisitions.

“Check Point has said that it is looking into SD-WAN, and given that all of its main competitors are active in this field, an acquisition does seem likely,” Babic said. “However, there may be some benefit of being independent of SD-WAN specialists as all of them are willing to work with Check Point.”

Just last week Hewlett Packard Enterprise (HPE) bought SD-WAN vendor Silverpeak for $925 million, and other independent SD-WAN specialists including Cato Networks, Versa, and Aryaka remain attractive M&A targets for Check Point, Babic added. “However I really don’t know who Check Point would be most likely to buy.”

Cato, like Check Point, is an Israeli company co-founded by a Check Point co-founder. Plus, Check Point’s recent acquisitions have all been Israel-based companies. “However, this doesn’t necessarily mean that Cato would be Check Point’s most likely target,” he said.

The report also notes that other network security vendors such as Barracuda Networks, Juniper Networks, SonicWall, and WatchGuard lag far behind the market-leading four. They are, however, also expanding their portfolios beyond network security to differentiate themselves in the market. Last month, for example, WatchGuard acquired Panda Security.

Still, these smaller players don’t have the same means as their larger counterparts to provide financial support for channel partners and customers during the COVID-19 pandemic. Cisco, for example, allows its customers to defer 95% of payments until 2021, and Palo Alto Networks created a financial services arm that offers financing for multi-year deals. This disparity, Analysys Mason says, may enable the top four vendors “to acquire technology and market access (and therefore accelerate their growth) at discounted prices.”