Acquisition activity in the cybersecurity space slowed in the first half of this year, according to Momentum Cyber.
The value of M&As in H1 was $4.1bn (£3.2bn), the firm said, compared with $6.2bn in the first half of 2017.
Q1 this year saw acquisitions to the value of $2.5bn, while Q2 saw $1.6bn.
Both quarters were dwarfed by the last quarter of Q4, which saw $11.5bn-worth of M&A deals completed.
10. Secdo acquired by Palo Alto Networks - $90m
In the first of two Palo Alto Networks acquisitions featured on this list, the US firm acquired Secdo for a fee which Momentum reported as $90m.
The Israeli firm, founded in 2014, specialises in end-point detection and response and also provides a platform for network visibility and analytics.
Speaking to CRN last year, Secdo CEO Shai Morag said that the firm was in the process of building out its UK channel, specifically targeting dedicated security resellers and managed security service providers.
On the acquisition by Palo Alto, Morag said: "We founded Secdo to dramatically increase visibility for security operations teams to reduce the time it takes to detect and respond to an alert.
"The combined capabilities of Secdo and Palo Alto Networks will provide customers with the capabilities they need to swiftly and accurately detect and respond to cyberattacks."
9. Dealflo acquired by OneSpan - $55m
London-based Dealflo was acquired by publicly listed OneSpan in May, in a deal worth $55m.
Dealflo was founded in 2008 and specialises in identity verification and financial agreement automation solutions. The firm counts Ford and BMW among its customers.
OneSpan is listed on New York's NASDAQ market and has a valuation of around $658m.
The firm's CEO Scott Clements said that Dealflo's capabilities will help it bolster its subscription revenues.
8. VictorOps acquired by Splunk - $120m
In a move more than double the size of the ninth-placed deal on this list, Splunk moved for incident management vendor VictorOps for $120m in June.
VictorOps provides a solution that centralises the flow of information throughout the incident life cycle, according to Momentum.
The platform provides access to real-time alerts and facilitates collaboration among team members to help resolve incidents faster.
At the time, Splunk CEO Doug Merritt said: "The combination of machine data analytics and artificial intelligence from Splunk with incident management from VictorOps creates a platform of engagement that will help modern development teams innovate faster and deliver better customer experiences."
7. IDQ acquired by SK Telecom - $130m
South Korean telecoms giant SK splashed out $65m for half of Geneva-based firm IDQ, valuing it at $130m.
IDQ claims to be the world leader in "quantum-safe crypto solutions", to protect data as it travels across a network.
"In a world where the technological landscape is being revolutionised by quantum physics, IDQ helps its customers to guarantee long-term security of their data through quantum-safe crypto solutions," its website states.
6. Wombat Security Technologies acquired by Proofpoint - $225m
Proofpoint snapped up cybersecurity awareness training vendor Wombat for $225m in February.
Publicly listed Proofpoint, currently worth around $6bn, said at the time of the deal that Wombat's tech would bolster its offering against human-based threats.
Wombat's solutions focus on training organisations' employees to follow best practices and help minimise the ways that attackers can pose a threat.
Wombat's education platform includes solutions to help combat attack methods including phishing.
Gary Steele, Proofpoint's CEO, said: "Because threat actors target employees as the weakest link, companies need to continuously train employees and arm them with real-time threat data."
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