Atika Capital Management LLC

Atika Capital Management LLC publishes a $798M, 180-name 13F whose defining structural feature is one of the largest single-stock positions at this scale: Vertiv (VRT, 21.0%, $168M) — the critical-infrastructure and data-center cooling company — claims more than one-fifth of the entire portfolio by itself. That level of concentration signals a genuine high-conviction thematic bet on AI data-center buildout. Around that anchor, the manager has built a quality-tech-and-healthcare overlay: Eli Lilly (LLY, 4.7%) in pharmaceuticals, Netflix (NFLX, 4.2%) in streaming, SATS (5.0%) in satellite communications, and XBI (SPDR S&P Biotech ETF, 6.8%) as the healthcare sector vehicle. With whaleScore of 54 and 80 total changes across 180 holdings in Q1, this is a genuine concentrated single-stock allocator — not a passive or factor-driven product.