Portfolio Co Investors 2026 for Mainsail Partners: investors, rounds, and co-investor patterns from StartupFundraising.com research, updated for 2026.
Mainsail Partners accounts for 11 tracked companies with verified cap-table data, 11 of which disclose round sizes totalling $814M. The median disclosed raise is $45M, and the largest is JobNimbus at $383M, ahead of Skimmer ($74M) and MirrorWeb ($67M).
The names that recur most often on these co-invested cap tables are Mainsail Partners (11 companies), Sumeru Equity Partners (1 company), Unbundled Capital (1 company), Maven Capital Partners (1 company), Northern Powerhouse Investment Fund (1 company). By latest disclosed round, the market skews Growth (7), Series B (1), Series A (1), Seed (1).