One William Street Capital Management, L.P. Institutional Portfolio (13F)

One William Street Capital Management, L.P.'s disclosed holdings carry a Herfindahl concentration index of 0.810 — mathematically equivalent to about 1 equally-sized positions, well below its 16 actual disclosed holdings. That gap points to a strategy built around a small core of high-conviction bets rather than broad diversification.

Position sizes vary widely across the portfolio (a coefficient of variation of 3.21), with a handful of outsized bets alongside many smaller positions.

Recent activity leans toward adding more aggressively to already-large existing positions than to newly initiated ones (a 30.8 percentage-point tilt) — a pattern consistent with a momentum-following approach.

Sector classification currently covers about 1% 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.