Institutional Manager · CIK 0001106832
CASTLEARK MANAGEMENT LLC
CHICAGO, IL · File #028-05573
Latest AUM
$3.41B
Positions
294
Top-10 Concentration
50.4%
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 |
|---|---|---|---|---|---|
| EXITED | ADVISORS INNER CIRCLE FD II | 00791R608 | -7,383,950 | -$322.1M | $0 |
| EXITED | NETFLIX INC | 64110L106 | -54,948 | -$65.9M | $0 |
| ADD | ELI LILLY & CO | LLY | +37,025 | +$39.8M | +$13.9M |
| ADD | SERVICENOW INC | NOW | +217,442 | +$33.3M | -$40.6M |
| NEW | ULTA BEAUTY INC | ULTA | +49,941 | +$30.2M | $0 |
| REDUCE | LAM RESEARCH CORP | LRCX | -131,244 | -$22.5M | +$18.8M |
| NEW | ADVANCED MICRO DEVICES INC | AMD | +104,746 | +$22.4M | $0 |
| EXITED | DEXCOM INC | 252131107 | -300,249 | -$20.2M | $0 |
| ADD | AMAZON COM INC | AMZN | +81,542 | +$18.8M | +$4.4M |
| ADD | BOOKING HOLDINGS INC | BKNG | +3,412 | +$18.3M | -$90,516 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 2025294 pos · $3.41B
- 13F HOLDINGS REPORTQ/E Sep 2025284 pos · $3.57B
- 13F HOLDINGS REPORTQ/E Jun 2025275 pos · $3.33B
- 13F HOLDINGS REPORTQ/E Mar 2025280 pos · $2.89B
- 13F HOLDINGS REPORTQ/E Dec 2024283 pos · $2.87B
- 13F HOLDINGS REPORTQ/E Sep 2024272 pos · $2.45B
- 13F HOLDINGS REPORTQ/E Jun 2024271 pos · $2.45B
- 13F HOLDINGS REPORTQ/E Mar 2024278 pos · $2.40B
- 13F HOLDINGS REPORTQ/E Dec 2023274 pos · $1.96B
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | NVIDIA CORPORATION | NVDA | 1,408,146 | $262.6M | 11.15% |
| 2 | MICROSOFT CORP | MSFT | 369,460 | $178.7M | 7.59% |
| 3 | ALPHABET INC | GOOG | 381,639 | $119.5M | 5.07% |
| 4 | AMAZON COM INC | AMZN | 472,149 | $109.0M | 4.63% |
| 5 | APPLE INC | AAPL | 387,041 | $105.2M | 4.47% |
| 6 | ELI LILLY & CO | LLY | 81,578 | $87.7M | 3.72% |
| 7 | SPDR SERIES TRUST | 78464A375 | 2,519,370 | $85.2M | 3.62% |
| 8 | META PLATFORMS INC | META | 122,415 | $80.8M | 3.43% |
| 9 | VANGUARD SCOTTSDALE FDS | 92206C771 | 1,705,540 | $80.3M | 3.41% |
| 10 | ISHARES TR | 46429B267 | 3,329,569 | $76.7M | 3.26% |
| 11 | BROADCOM INC | AVGO | 205,880 | $71.3M | 3.03% |
| 12 | LAM RESEARCH CORP | LRCX | 372,876 | $63.8M | 2.71% |
| 13 | SCHWAB CHARLES CORP | SCHW-PJ | 622,535 | $62.2M | 2.64% |
| 14 | VISA INC | V | 170,478 | $59.8M | 2.54% |
| 15 | MASTERCARD INCORPORATED | MA | 102,451 | $58.5M | 2.48% |
| 16 | SHOPIFY INC | SHOP | 345,382 | $55.6M | 2.36% |
| 17 | ARISTA NETWORKS INC | ANET | 411,277 | $53.9M | 2.29% |
| 18 | SERVICENOW INC | NOW | 270,420 | $41.4M | 1.76% |
| 19 | SPDR SERIES TRUST | 78468R101 | 1,334,080 | $39.1M | 1.66% |
| 20 | BLACKSTONE INC | BX | 244,268 | $37.7M | 1.60% |