Cybersecurity company Island has raised US$250 million in its series E funding round, increasing its valuation to US$4.8 billion.

The round was led by Coatue, with participation from existing investors including Sequoia Capital and Insight Partners.

Founded by Mike Fey and Dan Amiga, Island has now secured over US$730 million in total funding.

Island employs over 450 people, with 200 based in Tel Aviv. Fey, a former president and COO at Symantec, and Amiga, a founder of Fireglass, have established the company as a provider of secure enterprise browser solutions.