Bitcoin custody platform Onramp has successfully raised $12.5 million in a Series A funding round, achieving a pre-money valuation of $135 million. The funding round was led by Early Riders, with Michael Tanguma, who is both a partner at Early Riders and the CEO of Onramp, playing a pivotal role. Onramp utilizes a multi-institutional custodial model that requires joint authorization from multiple custodians to transfer Bitcoin assets, enhancing security. Its custodial partners include BitGo, Coincover, and Tetra Trust, which collaborate to ensure the secure management of Bitcoin holdings.