Merck & Co., Inc. — 13F Holdings & Portfolio
CIK 310158 · latest 13F-HR filed 2026-05-13
Merck & Co., Inc. manages $349.4M in 13F-reported U.S. long-equity assets across 14 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are MRNA (33.56%), PSNL (25.60%), KYMR (18.40%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 3 new positions, exited 1, added to 6, and trimmed 4.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$349.4M
Long-equity book
14
Distinct positions
2026-03-31
Filed 2026-05-13
+3 / −1 / ↑6 / ↓4
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- MODERNA INC$49.2M +72.3%
- KYMERA THERAPEUTICS INC$4.2M +7.0%
- ENTRADA THERAPEUTICS INC$4.1M +22.8%
- SUTRO BIOPHARMA INC$3.6M +115.3%
- ALECTOR INC$2.1M +37.8%
Top Trims
- PERSONALIS INC-$22.3M -20.0%
- EVAXION BIOTECH A/S-$1.3M -22.0%
- VIRIDIAN THERAPEUTICS INC-$1.1M -37.1%
- CARISMA THERAPEUTICS INC-$15.5K -24.4%
New Positions
- EIKON THERAPEUTICS INC$17.6M
- AKTIS ONCOLOGY INC$17.0M
- XILIO THERAPEUTICS INC$891.3K
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | MODERNA INC | MRNA | 60770K107 | $117.3M | 33.56% | 2,308,190 | SH |
| 2 | PERSONALIS INC | PSNL | 71535D106 | $89.5M | 25.60% | 14,044,943 | SH |
| 3 | KYMERA THERAPEUTICS INC | KYMR | 501575104 | $64.3M | 18.40% | 772,165 | SH |
| 4 | ENTRADA THERAPEUTICS INC | TRDA | 29384C908 | $22.0M | 6.28% | 1,739,768 | SH |
| 5 | EIKON THERAPEUTICS INC | EIKN | 282564103 | $17.6M | 5.05% | 1,666,666 | SH |
| 6 | AKTIS ONCOLOGY INC | AKTS | 01021M104 | $17.0M | 4.88% | 952,844 | SH |
| 7 | ALECTOR INC | ALEC | 014442107 | $7.6M | 2.18% | 3,545,719 | SH |
| 8 | SUTRO BIOPHARMA INC | STRO | 869367102 | $6.8M | 1.94% | 272,351 | SH |
| 9 | EVAXION BIOTECH A/S | — | 29970R204 | $4.5M | 1.29% | 1,214,126 | SH |
| 10 | VIRIDIAN THERAPEUTICS INC | VRDN | 92790C104 | $1.8M | 0.52% | 93,414 | SH |
| 11 | XILIO THERAPEUTICS INC | XLO | 98422T209 | $891.3K | 0.26% | 105,982 | SH |
| 12 | CARISMA THERAPEUTICS INC | CARM | 14216R101 | $47.9K | 0.01% | 1,473,240 | SH |
| 13 | NEUPHORIA THERAPEUTICS INC | NEUP | 64136E102 | $40.8K | 0.01% | 10,027 | SH |
| 14 | TUHURA BIOSCIENCES | HURA | 898920103 | $34.8K | 0.01% | 19,445 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-13 | $349.4M | 14 | 0000310158-26-000141 |
| 2025-12-31 | 2026-02-17 | $276.3M | 12 | 0000310158-26-000055 |
| 2025-09-30 | 2025-11-12 | $228.0M | 13 | 0000310158-25-000063 |