Analysis
General Catalyst was the most active post-seed investor in the US in the second quarter of 2026 with 39 deals, according to Crunchbase News, followed by Y Combinator with 34 and Andreessen Horowitz with 28. More than two-thirds of the deals from this top tier went into AI-focused startups -- confirmation, in raw deal-count terms, of just how thoroughly AI has come to dominate where the most active investors are putting capital.
At least a dozen investors led or co-led six or more rounds during the quarter, a level of concentration among a relatively small set of brand-name firms that's become the defining feature of the 2026 venture market. That pattern shows up starkly in the quarter's single largest financing: Anthropic's $50 billion Series H in May drew an unusually large syndicate, with ten different investors co-leading pieces of the round, while Google separately led a $10 billion tranche and Amazon led a $5 billion tranche -- meaning a single company's round effectively absorbed a meaningful share of several top firms' entire quarterly deal activity.
Y Combinator's dominance at the seed stage is its own story: more than 225 seed, pre-seed and convertible-note deals in a single quarter is a volume no traditional seed fund comes close to matching, reinforcing YC's position less as a peer to firms like Antler or LvlUp Ventures and more as its own category of pre-seed infrastructure for the startup ecosystem.
For founders raising in the current market, the practical read is that a shrinking number of firms are writing the majority of post-seed checks, and most of them are prioritizing AI-native companies -- a non-AI startup raising a Series A or B in this environment is competing for attention from investors whose calendars are dominated by AI diligence. For LPs, the concentration of top-tier deal flow into General Catalyst, YC and a16z specifically raises the familiar question of whether returns will concentrate as heavily as deal activity has -- a pattern that historically hasn't always held.
