Institutional Manager · CIK 0001103646
CSS LLC/IL
CHICAGO, IL · File #028-15940
Latest AUM
$2.25B
Positions
999
Top-10 Concentration
51.2%
Filings
9
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| ADD | ECHOSTAR CORP | SATS | +23,417,044 | +$78.3M | +$12.8M |
| NEW | WESTERN DIGITAL CORP | WDC | +330,000 | +$56.8M | $0 |
| EXITED | SANDISK CORP | 80004C950 | -330,000 | -$37.0M | $0 |
| REDUCE | IONIS PHARMACEUTICALS INC | IONS | -21,071,000 | -$33.5M | +$5.0M |
| REDUCE | LUMENTUM HLDGS INC | LITE | -6,000,000 | -$31.9M | +$39.2M |
| ADD | BRIDGEBIO PHARMA INC | BBIO | +25,000,000 | +$28.1M | +$203,546 |
| REDUCE | WAYFAIR INC | W | -12,067,000 | -$27.7M | +$3.8M |
| ADD | BANK AMERICA CORP | 060505682 | +20,048 | +$25.0M | -$120,833 |
| REDUCE | IONIS PHARMACEUTICALS INC | IONS | -17,590,000 | -$24.2M | +$9.0M |
| REDUCE | STRIDE INC | LRN | -16,974,000 | -$23.2M | -$39.9M |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 2025999 pos · $2.25B
- 13F HOLDINGS REPORTQ/E Sep 2025985 pos · $2.23B
- 13F HOLDINGS REPORTQ/E Jun 2025953 pos · $2.14B
- 13F HOLDINGS REPORTQ/E Mar 2025909 pos · $1.82B
- 13F HOLDINGS REPORTQ/E Dec 2024955 pos · $2.27B
- 13F HOLDINGS REPORTQ/E Sep 2024820 pos · $2.19B
- 13F HOLDINGS REPORTQ/E Jun 2024875 pos · $1.96B
- 13F HOLDINGS REPORTQ/E Mar 2024806 pos · $1.73B
- 13F HOLDINGS REPORTQ/E Dec 2023808 pos · $1.52B
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | ECHOSTAR CORP | SATS | 37,825,753 | $126.5M | 9.67% |
| 2 | LUMENTUM HLDGS INC | LITE | 40,464,000 | $115.0M | 8.79% |
| 3 | JAZZ INVESTMENTS I LTD | 472145AF8 | 65,074,000 | $75.4M | 5.76% |
| 4 | IONIS PHARMACEUTICALS INC | IONS | 44,792,000 | $61.5M | 4.70% |
| 5 | WESTERN DIGITAL CORP | WDC | 330,000 | $56.8M | 4.34% |
| 6 | PEABODY ENGR CORP | 704551AD2 | 30,268,000 | $50.9M | 3.89% |
| 7 | SPDR S&P 500 ETF TR | SPY | 72,700 | $49.6M | 3.79% |
| 8 | LIVE NATION ENTERTAINMENT IN | LYV | 32,756,000 | $47.6M | 3.64% |
| 9 | EQUINOX GOLD CORP | EQX | 18,936,000 | $44.4M | 3.39% |
| 10 | STRATEGY INC | STRK | 281,400 | $42.8M | 3.27% |
| 11 | LUMENTUM HLDGS INC | LITE | 7,500,000 | $39.9M | 3.05% |
| 12 | TRANSOCEAN INC | RIG | 27,333,000 | $37.6M | 2.87% |
| 13 | BRIDGEBIO PHARMA INC | BBIO | 26,500,000 | $29.8M | 2.28% |
| 14 | BANK AMERICA CORP | 060505682 | 23,661 | $29.5M | 2.26% |
| 15 | GAMESTOP CORP NEW | GME-WT | 1,457,500 | $29.3M | 2.24% |
| 16 | SPDR GOLD TR | GLD | 62,000 | $24.6M | 1.88% |
| 17 | SPDR S&P 500 ETF TR | SPY | 32,500 | $22.2M | 1.69% |
| 18 | GUARDANT HEALTH INC | GH | 11,000,000 | $20.1M | 1.54% |
| 19 | VANGUARD INDEX FDS | 922908363 | 31,650 | $19.8M | 1.52% |
| 20 | AMERICAN AIRLS GROUP INC | 02376R102 | 1,211,900 | $18.6M | 1.42% |