a16z Ecosystem Partner David Booth: The Most Important Skill in the Industry and the World is Identifying Things Before Market Pricing
David Booth, ecosystem partner at Andreessen Horowitz, explained the logic behind the co-sign product Cosign in the firm's podcast: the most important skill in our town, industry, and the world is identifying things before market pricing. Investors identify companies, recruiters and founders identify people, and sometimes products. This "early discovery" is not recorded on a leaderboard, unlike who finds a café first; angels seek non-consensus yet correct insights and are rewarded for it.
Booth uses himself as an example: if he truly believes in someone that others have not yet heard of, he can introduce that person to Josh Elman. The introduction is accepted not because the other party knows the person, but because they see Booth putting his reputation on the line for this referral. The referred can use the phrase "David co-signed for me" to send cold emails, and Elman may respond as a result. He calls this the wheel that lubricates social capital. If he co-signs for two people, they may meet, team up, hire each other, or invest in each other without him even knowing.
In the same conversation, Erik Torenberg, Olivia Moore, and former LinkedIn employee Elman launched Cosign: a career reputation product for the startup community that records who you are willing to put your name behind, which companies, and which products. Joining requires a co-sign or direct application. The product has private and public lists: the former is for people you want to collaborate with in the future, while the latter is a transferable endorsement list. Profiles aggregate public financing, postings, and job changes without requiring prior registration from the individual. Moore mentioned that one of her job postings received 2,000 responses and expects that browser agents will push the number to 100,000, making human endorsements scarcer after AI floods the submissions.
Booth will return to the Bay Area from New Zealand's Blackbird in October 2025 to become a16z partner and ecosystem head, having previously founded On Deck and participated early in AngelList. He has long broken down venture capital into three components: capital, credentials, and community, and has written priority attachments into institutional work: top firms provide credibility bridges for startups that lack reputation, which can then be exchanged for hiring, clients, and branding. Cosign is his transformation of "co-signing mortgages" from a metaphor into a product: reputation can be repurposed like a guarantor.
Mechanically, this turns early judgments that cannot be recorded into a browsable map. Buyers are recruiters overwhelmed by AI submissions, angels who need to place bets before consensus forms, and early founders needing a transferable reputation; sellers are a16z's new media and ecosystem lines, using podcasts, directories, and co-sign maps to productize the informal networks between LPs and projects. Funds do not directly buy tokens; they buy who appears on whose public co-sign list. Beneficiaries are those already co-signed by high-reputation nodes, and platforms that turn "early discovery" into a citable asset; under pressure are LinkedIn-style universal endorsements and job applications that can be generated in bulk. The interest on social capital is settled the moment a cold email is opened, and the map merely leaves the settlement receipt online.
Source: Public Information
ABAB AI Insight
Booth's career trajectory involves separately selling the community functions within accelerators: On Deck sells tickets to enter the room, a16z Build sells dinners and front doors to cross-chapter talent, and Cosign sells portable co-signs. After Andreessen Horowitz turned venture capital into a platform business, what was missing was a map that does not belong to LinkedIn but clearly states "who is willing to collaborate again." Elman, who helped LinkedIn with job products, now critiques the dilution of universal career network signals. The firm uses its own partners as the first batch of guarantors, effectively using its brand to cold-start the map.
The capital path is reputation leverage. Co-signing does not transfer equity but rather the probability of opening the next private message. An angel check is a capital co-sign, a tweet is a dissemination co-sign, and an introduction is a channel co-sign; Cosign aims to write these three into the same edge. a16z does not rely on this product to charge intermediary fees openly; instead, it relies on more quality individuals being preferentially attached to the fund ecosystem, thereby reducing the search costs for finding projects and people. After AI has turned application letters into free commodities, the only thing that cannot be bulk-faked is a specific person's willingness to repeatedly bet their name.
Analogous to the PayPal mafia hiring each other, Y Combinator directories, and early AngelList follow-on signals. Paul Graham's inclusion of Sam Altman among the five founders in 2009 was a co-sign that was later recorded in history. After LinkedIn made endorsements a button that everyone could click, the signal decayed; Cosign makes the button scarce by setting access thresholds. The industry phase is control: the discovery rights shift from open dynamics back to who has the authority to co-sign whom. The Bay Area's mantra "non-consensus yet correct" has finally taken on a product form scoreboard, even though Booth verbally claims there is no ranking of trendsetters in the world.
Structural judgment is the transfer of pricing power. The mechanism shifts the early premium of talent and projects from un-auditable memory to transferable co-sign edges. Pricing power shifts from those with the largest address books to those willing to publicly consume reputation. The market first rewards discoverers, and the product then provides a receipt for that discovery.
ABAB News · Cognitive Laws
When the market has not yet priced, names are bridge loans.
AI makes applications cheaper, while human endorsements become more expensive.
Co-signing two people can complete a transaction while the guarantor is asleep.