Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
263 institutional managers reported holding TNDM for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 59%. 39 opened new positions; 41 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 10.69M | 15.63% | $204.7M | trimmed -4.1% | 2013 Q4 |
| Vanguard Group | 7.61M | 11.12% | $145.6M | added +3.6% | 2013 Q4 |
| Sessa Capital IM, L.p. (focused) | 4.73M | 6.92% | $90.6M | trimmed -5.4% | 2025 Q1 |
| ArrowMark Colorado Holdings LLC | 3.10M | 4.54% | $59.4M | added +7.4% | 2023 Q3 |
| Gw&k Investment Management, LLC | 2.69M | 3.93% | $51.5M | added +0.5% | 2023 Q4 |
| State Street | 2.66M | 3.89% | $51.0M | added +0.8% | 2018 Q1 |
| Driehaus Capital Management LLC | 2.30M | 3.37% | $44.1M | added +43.1% | 2025 Q4 |
| Goldman Sachs | 2.22M | 3.24% | $42.5M | added +31.8% | 2018 Q2 |
| UBS | 2.22M | 3.24% | $42.4M | added +280.3% | 2013 Q4 |
| Citadel Advisors | 2.19M | 3.21% | $42.0M | added +5% | 2018 Q2 |
| Paradice Investment Management LLC (focused) | 2.04M | 2.99% | $39.1M | trimmed -1.7% | 2023 Q2 |
| Two Sigma | 1.86M | 2.73% | $35.7M | added +55.2% | 2022 Q1 |
| Geode Capital | 1.68M | 2.46% | $32.2M | added +1.8% | 2013 Q4 |
| Jennison Associates LLC | 1.66M | 2.42% | $31.8M | trimmed -18% | 2023 Q2 |
| Jacobs Levy Equity Management, INC | 1.52M | 2.23% | $29.2M | trimmed -7.8% | 2022 Q4 |
| Marshall Wace | 1.44M | 2.11% | $27.6M | added +64.8% | 2025 Q4 |
| Morgan Stanley | 1.36M | 1.99% | $26.0M | trimmed -34.7% | 2013 Q4 |
| Freestone Grove Partners LP | 1.33M | 1.95% | $25.5M | trimmed -7.8% | 2025 Q3 |
| First Light Asset Management, LLC (focused) | 1.31M | 1.92% | $25.2M | added +20.7% | 2025 Q4 |
| Baillie Gifford | 1.09M | 1.59% | $20.9M | trimmed -4.9% | 2018 Q3 |
| Wellington Management | 1.04M | 1.52% | $20.0M | added +960.7% | 2025 Q4 |
| Voya Investment Management LLC | 804.1k | 1.18% | $15.4M | added +151.7% | 2018 Q2 |
| D. E. Shaw | 783.9k | 1.15% | $15.0M | trimmed -8.2% | 2025 Q2 |
| Soleus Capital Management, L.p. | 783.0k | 1.15% | $15.0M | opened | 2026 Q1 |
| Defilade Capital Management, L.p. (focused) | 761.9k | 1.11% | $14.6M | opened | 2026 Q1 |
| Millennium Management | 761.7k | 1.11% | $14.6M | added +30.5% | 2018 Q1 |
| FMR (Fidelity) | 714.0k | 1.04% | $13.7M | added +6.1% | 2018 Q3 |
| Northern Trust | 706.6k | 1.03% | $13.5M | added +2.2% | 2013 Q4 |
| Royce & Associates | 696.6k | 1.02% | $13.3M | added +7.1% | 2025 Q3 |
| Quantinno Capital Management LP | 653.9k | 0.96% | $12.5M | added +123.5% | 2023 Q4 |
| Charles Schwab Investment Management | 642.6k | 0.94% | $12.3M | trimmed -0.6% | 2018 Q2 |
| ExodusPoint | 632.9k | 0.93% | $12.1M | opened | 2026 Q1 |
| Holocene Advisors | 477.4k | 0.70% | $9.1M | added +2807.5% | 2025 Q4 |
| Aberdeen Group plc | 434.0k | 0.64% | $8.3M | trimmed -20.7% | 2024 Q3 |
| Barclays PLC | 421.2k | 0.62% | $8.1M | trimmed -54.1% | 2013 Q4 |
| Point72 | 420.5k | 0.61% | $8.1M | opened | 2025 Q3 |
| Frontier Capital Management CO LLC | 397.2k | 0.58% | $7.6M | trimmed -3.7% | 2015 Q1 |
| Bank OF America CORP /DE/ | 373.2k | 0.55% | $7.1M | trimmed -46.9% | 2013 Q4 |
| Nuveen | 363.8k | 0.53% | $7.0M | trimmed -35.4% | 2019 Q2 |
| Dafna Capital Management LLC | 355.2k | 0.52% | $6.8M | unchanged | 2023 Q2 |
| First Trust Advisors LP | 342.7k | 0.50% | $6.6M | opened | 2024 Q1 |
| BNY Mellon | 336.3k | 0.49% | $6.4M | trimmed -3.8% | 2013 Q4 |
| AQR Capital | 331.9k | 0.48% | $6.4M | trimmed -2.3% | 2024 Q2 |
| Principal Financial Group INC | 331.5k | 0.48% | $6.3M | added +2.2% | 2018 Q3 |
| Invesco | 294.1k | 0.43% | $5.6M | added +5.9% | 2018 Q2 |
| Acadian Asset Management | 278.1k | 0.41% | $5.3M | trimmed -29.2% | 2024 Q3 |
| Sector Gamma AS (focused) | 267.1k | 0.39% | $5.1M | unchanged | 2025 Q1 |
| Edmond DE Rothschild Holding S.a. | 258.2k | 0.38% | $4.9M | unchanged | 2025 Q1 |
| Beaconlight Capital, LLC (focused) | 253.9k | 0.37% | $4.9M | opened | 2026 Q1 |
| Trexquant Investment LP | 249.3k | 0.36% | $4.8M | added +142.7% | 2023 Q3 |
Largest 50 of 263 shown; the full ranked, searchable register is at boothcheck.com/holders/TNDM. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.