13D Management LLC 13F Filings Tracker & Analysis

13D Management LLC's disclosed holdings carry a Herfindahl concentration index of 0.085 — mathematically equivalent to about 12 equally-sized positions, close to its 13 actual disclosed holdings. Value is spread relatively evenly across the portfolio rather than concentrated in a handful of names.

Position sizes are fairly uniform across the portfolio (a coefficient of variation of 0.33), suggesting a disciplined, rules-based approach to how much capital goes into each idea.

Recent activity leans toward initiating meaningfully larger new positions than it adds to existing ones (a 10.7 percentage-point tilt) — a pattern consistent with a more contrarian, new-idea-driven approach.

Sector classification currently covers about 70% of this portfolio's disclosed value; the remainder includes holdings (e.g. unmapped tickers, options, or other security types) not yet covered by our sector mapping.