Institutional Manager · CIK 0001125725
GAGNON SECURITIES LLC
New York, NY · File #028-06377
Latest AUM
$491.1M
Positions
86
Top-10 Concentration
49.7%
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 |
|---|---|---|---|---|---|
| REDUCE | FRESHWORKS INC | FRSH | -635,807 | -$7.8M | +$895,593 |
| REDUCE | AIR LEASE CORP | AIIR | -108,661 | -$7.0M | +$351,277 |
| REDUCE | INTUITIVE SURGICAL INC | ISRG | -11,562 | -$6.5M | +$5.2M |
| ADD | FIVE9 INC | FIVN | +326,323 | +$6.5M | -$1.2M |
| EXITED | POWER SOLUTIONS INTL INC | 73933G202 | -64,770 | -$6.4M | $0 |
| ADD | CARMAX INC | KMX | +94,448 | +$3.6M | -$1.4M |
| REDUCE | BOSTON BEER INC | SAM | -15,153 | -$3.0M | -$350,365 |
| ADD | AMPLITUDE INC | AMPL | +188,139 | +$2.2M | +$439,229 |
| REDUCE | DOUBLEVERIFY HLDGS INC | DV | -188,253 | -$2.2M | -$367,156 |
| ADD | TREACE MED CONCEPTS INC | 89455T109 | +852,337 | +$2.1M | -$9.6M |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 202586 pos · $491.1M
- 13F HOLDINGS REPORTQ/E Sep 202586 pos · $498.5M
- 13F HOLDINGS REPORTQ/E Jun 202587 pos · $492.4M
- 13F HOLDINGS REPORTQ/E Mar 202598 pos · $454.5M
- 13F HOLDINGS REPORTQ/E Dec 202491 pos · $496.3M
- 13F HOLDINGS REPORTQ/E Sep 2024102 pos · $504.4M
- 13F HOLDINGS REPORTQ/E Jun 202497 pos · $444.0M
- 13F HOLDINGS REPORTQ/E Mar 202498 pos · $422.5M
- 13F HOLDINGS REPORTQ/E Dec 202397 pos · $399.1M
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | CAREDX INC | CDNA | 1,774,890 | $33.4M | 7.02% |
| 2 | GENEDX HOLDINGS CORP | WGSWW | 253,534 | $33.0M | 6.92% |
| 3 | AIR LEASE CORP | AIIR | 496,957 | $31.9M | 6.70% |
| 4 | ENSIGN GROUP INC | ENSG | 180,549 | $31.5M | 6.60% |
| 5 | AMERESCO INC | AMRC | 832,884 | $24.4M | 5.12% |
| 6 | INTUITIVE SURGICAL INC | ISRG | 31,797 | $18.0M | 3.78% |
| 7 | EXACT SCIENCES CORP | 30063P105 | 167,414 | $17.0M | 3.57% |
| 8 | ENTERPRISE PRODS PARTNERS L P | 293792107 | 527,601 | $16.9M | 3.55% |
| 9 | BLACKLINE INC | BL | 279,398 | $15.4M | 3.24% |
| 10 | PROFOUND MED CORP | PROF | 1,944,061 | $15.3M | 3.21% |
| 11 | FRESHWORKS INC | FRSH | 1,230,011 | $15.1M | 3.16% |
| 12 | NAVIGATOR HLDGS LTD | NVGS | 861,854 | $14.9M | 3.13% |
| 13 | EQUINIX INC | EQIX | 17,142 | $13.1M | 2.76% |
| 14 | PACIRA BIOSCIENCES INC | PCRX | 501,211 | $13.0M | 2.72% |
| 15 | BIOLIFE SOLUTIONS INC | BLFS | 534,357 | $12.9M | 2.71% |
| 16 | FIVE9 INC | FIVN | 625,726 | $12.5M | 2.63% |
| 17 | CARMAX INC | KMX | 320,077 | $12.4M | 2.60% |
| 18 | CHEESECAKE FACTORY INC | CAKE | 226,594 | $11.4M | 2.40% |
| 19 | CARGURUS INC | CARG | 270,822 | $10.4M | 2.18% |
| 20 | GENERAC HLDGS INC | GNRC | 75,593 | $10.3M | 2.16% |