Who owns Ambarella (AMBA)
Which tracked institutional funds hold AMBA, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See AMBA company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
50 tracked funds added or opened AMBA while 132 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
AMBA’s largest tracked holder by dollar value, VANGUARD GROUP INC, sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes AMBA more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in AMBA divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 303 tracked filers holding AMBA, 172 increased or opened the position and 165 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in AMBA between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 23
- VANGUARD PORTFOLIO MANAGEMENT LLC$191M
- VANGUARD CAPITAL MANAGEMENT LLC$93M
- FIFTHDELTA Ltd$28M
- Woodline Partners LP$18M
- VANGUARD FIDUCIARY TRUST CO$15M
- HAWK RIDGE CAPITAL MANAGEMENT LP$14M
Full exits 37
- VANGUARD GROUP INC$388M
- Jericho Capital Asset Management L.P.$112M
- FULLER & THALER ASSET MANAGEMENT, INC.$60M
- Slate Path Capital LP$58M
- Driehaus Capital Management LLC$26M
- SEGALL BRYANT & HAMILL, LLC$13M
Largest adds
- MILLENNIUM MANAGEMENT LLC$66M
- Walleye Capital LLC$10M
- D. E. Shaw & Co., Inc.$10M
- CITADEL ADVISORS LLC$10M
- AQR CAPITAL MANAGEMENT LLC$8M
- MANUFACTURERS LIFE INSURANCE COMPANY, THE$6M
Largest trims
- BlackRock, Inc.$76M
- BARCLAYS PLC$48M
- Squarepoint Ops LLC$33M
- UBS Group AG$29M
- OBERWEIS ASSET MANAGEMENT INC/$29M
- Point72 Asset Management, L.P.$28M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 3,944,592 | $338M | 10.9% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 2,598,976 | $223M | 7.2% | 2026-Q2 |
| STATE STREET CORP added | 2,562,733 | $220M | 7.1% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 3,716,863 | $191M | 6.2% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 1,814,603 | $93M | 3.0% | 2026-Q1 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 1,586,082 | $82M | 2.6% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,029,229 | $53M | 1.7% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 926,468 | $48M | 1.5% | 2026-Q1 |
| Legal & General Group Plc added | 926,396 | $48M | 1.5% | 2026-Q1 |
| D. E. Shaw & Co., Inc. added | 515,084 | $44M | 1.4% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 495,583 | $43M | 1.4% | 2026-Q2 |
| MORGAN STANLEY trimmed | 724,655 | $37M | 1.2% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 638,587 | $33M | 1.1% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. added | 600,506 | $31M | 1.0% | 2026-Q1 |
| EXCHANGE TRADED CONCEPTS, LLC added | 571,580 | $29M | 0.9% | 2026-Q1 |
| FIFTHDELTA Ltd new | 546,538 | $28M | 0.9% | 2026-Q1 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 541,901 | $28M | 0.9% | 2026-Q1 |
| FMR LLC added | 316,013 | $27M | 0.9% | 2026-Q2 |
| Nuveen, LLC added | 487,820 | $25M | 0.8% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 481,758 | $25M | 0.8% | 2026-Q1 |
| Stephens Investment Management Group LLC trimmed | 475,141 | $24M | 0.8% | 2026-Q1 |
| Squarepoint Ops LLC trimmed | 460,580 | $24M | 0.8% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 473,762 | $23M | 0.7% | 2026-Q1 |
| PINNACLE ASSOCIATES LTD added | 430,249 | $22M | 0.7% | 2026-Q1 |
| ALGERT GLOBAL LLC added | 409,220 | $21M | 0.7% | 2026-Q1 |
| Handelsbanken Fonder AB added | 396,690 | $20M | 0.7% | 2026-Q1 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. added | 384,796 | $20M | 0.6% | 2026-Q1 |
| NORTHERN TRUST CORP added | 374,780 | $19M | 0.6% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 364,429 | $19M | 0.6% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 363,291 | $19M | 0.6% | 2026-Q1 |
| Woodline Partners LP trimmed | 349,479 | $18M | 0.6% | 2026-Q1 |
| UBS Group AG trimmed | 314,046 | $16M | 0.5% | 2026-Q1 |
| OBERWEIS ASSET MANAGEMENT INC/ trimmed | 295,185 | $15M | 0.5% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 289,849 | $15M | 0.5% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 284,289 | $15M | 0.5% | 2026-Q1 |
| HAWK RIDGE CAPITAL MANAGEMENT LP new | 276,100 | $14M | 0.5% | 2026-Q1 |
| T. Rowe Price Investment Management, Inc. new | 257,800 | $13M | 0.4% | 2026-Q1 |
| MARSHALL WACE, LLP trimmed | 249,542 | $13M | 0.4% | 2026-Q1 |
| Walleye Capital LLC added | 210,934 | $11M | 0.3% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 209,817 | $11M | 0.3% | 2026-Q1 |
| Point72 Asset Management, L.P. trimmed | 117,943 | $10M | 0.3% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 110,300 | $9M | 0.3% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 186,296 | $9M | 0.3% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 153,741 | $8M | 0.3% | 2026-Q1 |
| Freemont Management S.A. added | 135,800 | $7M | 0.2% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 132,938 | $7M | 0.2% | 2026-Q1 |
| Invesco Ltd. trimmed | 79,161 | $7M | 0.2% | 2026-Q2 |
| WESTERLY CAPITAL MANAGEMENT, LLC added | 130,000 | $7M | 0.2% | 2026-Q1 |
| MAIRS & POWER INC new | 117,581 | $6M | 0.2% | 2026-Q1 |
| Shannon River Fund Management LLC trimmed | 114,940 | $6M | 0.2% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 112,192 | $6M | 0.2% | 2026-Q1 |
| Portolan Capital Management, LLC added | 108,749 | $6M | 0.2% | 2026-Q1 |
| Hillsdale Investment Management Inc. added | 107,000 | $6M | 0.2% | 2026-Q1 |
| Robeco Schweiz AG trimmed | 104,154 | $5M | 0.2% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 95,460 | $5M | 0.2% | 2026-Q1 |
| Engineers Gate Manager LP trimmed | 93,943 | $5M | 0.2% | 2026-Q1 |
| Allianz Asset Management GmbH new | 92,600 | $5M | 0.2% | 2026-Q1 |
| SWS Partners added | 91,437 | $5M | 0.2% | 2026-Q1 |
| SEI INVESTMENTS CO added | 89,139 | $5M | 0.1% | 2026-Q1 |
| ArrowMark Colorado Holdings LLC added | 89,000 | $5M | 0.1% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 88,320 | $5M | 0.1% | 2026-Q1 |
| PANAGORA ASSET MANAGEMENT INC new | 87,167 | $4M | 0.1% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 83,104 | $4M | 0.1% | 2026-Q1 |
| ESSEX INVESTMENT MANAGEMENT CO LLC trimmed | 82,387 | $4M | 0.1% | 2026-Q1 |
| Mitsubishi UFJ Asset Management Co., Ltd. added | 81,909 | $4M | 0.1% | 2026-Q1 |
| Swiss National Bank added | 80,833 | $4M | 0.1% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 77,413 | $4M | 0.1% | 2026-Q1 |
| LORD, ABBETT & CO. LLC trimmed | 76,646 | $4M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC added | 5,480,285 | $388M | 12.5% | 2025-Q4 stale |
| Jericho Capital Asset Management L.P. added | 1,587,081 | $112M | 3.6% | 2025-Q4 stale |
| FULLER & THALER ASSET MANAGEMENT, INC. trimmed | 848,092 | $60M | 1.9% | 2025-Q4 stale |
| Slate Path Capital LP new | 814,400 | $58M | 1.9% | 2025-Q4 stale |
| Kodai Capital Management LP added | 904,536 | $46M | 1.5% | 2025-Q1 stale |
| AXA Investment Managers S.A. new | 332,581 | $27M | 0.9% | 2025-Q3 stale |
| Driehaus Capital Management LLC trimmed | 366,251 | $26M | 0.8% | 2025-Q4 stale |
| AXA S.A. trimmed | 356,992 | $24M | 0.8% | 2025-Q2 stale |
| SG Capital Management LLC added | 232,713 | $19M | 0.6% | 2025-Q3 stale |
| BAILLIE GIFFORD & CO trimmed | 259,380 | $17M | 0.6% | 2025-Q2 stale |
| Assenagon Asset Management S.A. trimmed | 257,899 | $17M | 0.5% | 2025-Q2 stale |
| SEGALL BRYANT & HAMILL, LLC trimmed | 178,097 | $13M | 0.4% | 2025-Q4 stale |
| INTRINSIC EDGE CAPITAL MANAGEMENT LLC new | 210,000 | $11M | 0.3% | 2025-Q1 stale |
| Potrero Capital Research LLC added | 148,537 | $11M | 0.3% | 2025-Q4 stale |
| LMR Partners LLP added | 150,000 | $10M | 0.3% | 2025-Q2 stale |
| Tairen Capital Ltd trimmed | 146,000 | $10M | 0.3% | 2025-Q2 stale |
| S Squared Technology, LLC trimmed | 128,551 | $9M | 0.3% | 2025-Q4 stale |
| NEUBERGER BERMAN GROUP LLC trimmed | 120,677 | $8M | 0.3% | 2025-Q2 stale |
| Tributary Capital Management, LLC trimmed | 107,508 | $8M | 0.2% | 2025-Q4 stale |
| Stanley-Laman Group, Ltd. new | 111,164 | $7M | 0.2% | 2025-Q2 stale |
| GLENVIEW CAPITAL MANAGEMENT, LLC new | 100,000 | $7M | 0.2% | 2025-Q4 stale |
| Hel Ved Capital Management Ltd trimmed | 103,870 | $7M | 0.2% | 2025-Q2 stale |
| Jain Global LLC added | 101,616 | $7M | 0.2% | 2025-Q2 stale |
| Cubist Systematic Strategies, LLC added | 120,432 | $6M | 0.2% | 2025-Q1 stale |
| Atom Investors LP added | 68,487 | $6M | 0.2% | 2025-Q3 stale |
| READYSTATE ASSET MANAGEMENT LP added | 76,879 | $5M | 0.2% | 2025-Q4 stale |
| TUDOR INVESTMENT CORP ET AL added | 107,764 | $5M | 0.2% | 2025-Q1 stale |
| Jump Financial, LLC added | 63,053 | $5M | 0.2% | 2025-Q3 stale |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 71,200 | $5M | 0.2% | 2025-Q2 stale |
| Meridiem Capital Partners LP new | 89,720 | $5M | 0.1% | 2025-Q1 stale |
| AIGH Capital Management LLC new | 50,000 | $4M | 0.1% | 2025-Q3 stale |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 57,338 | $4M | 0.1% | 2025-Q4 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.