01 Advisors

Adam Bain leads the firm's investment team and day-to-day decision-making from San Francisco. Dick Costolo remains involved in sourcing and advising portfolio companies but operates from the East Coast. The partnership does not maintain a formal investment committee beyond the two founders; deal approvals require consensus between Costolo and Bain.

Deal flow at 01 Advisors is primarily generated through the founders' personal networks among technology operators, founders, and fellow investors, many of whom worked with Costolo and Bain at Twitter, Google, or portfolio companies. The firm does not appear to operate a systematic outbound origination program and instead relies on inbound referrals and the co-investor relationships built during Costolo and Bain's decade in Silicon Valley leadership roles.

The firm targets Series B through late-stage venture rounds, with a stated focus on companies that have achieved product-market fit and require operational scaling support. Check sizes have ranged from roughly $10 million to $50 million per deal based on publicly reported rounds, with flexibility to lead or co-lead depending on the syndicate. Early-stage seed investing is not a material component of the strategy.

01 Advisors has not publicly disclosed a sector-exclusion policy. However, the firm's known portfolio does not include biotechnology, hard-science ventures, or capital-intensive industrial businesses — the observable pattern is concentrated in enterprise software, financial technology, and digitally native consumer platforms where C-suite operating experience is a direct value-add.

The firm is distinct from Twitter Inc. and has no formal relationship with the company. Costolo and Bain's operating history is the foundation of their advisory value proposition, and several portfolio-company founders have cited that experience as a reason for selecting 01 Advisors as an investor. No Twitter corporate affiliation, preferred access, or exclusive deal-flow arrangement exists between the two entities.