Ambarella, Inc.
US ˙ NasdaqGS ˙ KYG037AX1015

SecurityAMBA / Ambarella, Inc.
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership17,898 shares
Latest Disclosed Value $ 921,300
Janus Henderson Group Plc ownership in AMBA / Ambarella, Inc.

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 17,898 shares of Ambarella, Inc. (US:AMBA) valued at $921,300 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 17,898 shares of Ambarella, Inc.. This represents a change in shares of 0.00% during the quarter. The current value of the position is $1,289,551 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-18 2026-03-31 13F/A-1 AMBARELLA SHS G037AX101 17,898 0 0.00 921 -27.31 0.0004
2026-02-17 2025-12-31 13F AMBARELLA SHS G037AX101 17,898 0 0.00 1,268 -14.22 0.0006
2025-11-14 2025-09-30 13F AMBARELLA SHS G037AX101 17,898 0 0.00 1,478 24.96 0.0007
2025-08-14 2025-06-30 13F AMBARELLA SHS G037AX101 17,898 -14,709 -45.11 1,182 -28.32 0.0006
2025-05-15 2025-03-31 13F AMBARELLA SHS G037AX101 32,607 3,416 11.70 1,650 -22.29 0.0009
2025-02-14 2024-12-31 13F AMBARELLA SHS G037AX101 29,191 0 0.00 2,123 28.92 0.0011
2024-11-14 2024-09-30 13F AMBARELLA SHS G037AX101 29,191 823 2.90 1,647 7.65 0.0008
2024-08-14 2024-06-30 13F AMBARELLA SHS G037AX101 28,368 -559 -1.93 1,529 4.23 0.0008
2024-05-15 2024-03-31 13F AMBARELLA SHS G037AX101 28,927 -408,310 -93.38 1,468 -94.53 0.0008
2024-02-14 2023-12-31 13F AMBARELLA SHS G037AX101 437,237 -3,543 -0.80 26,796 14.65 0.0160
2023-11-14 2023-09-30 13F AMBARELLA SHS G037AX101 440,780 -26,476 -5.67 23,372 -40.20 0.0153
2023-08-14 2023-06-30 13F AMBARELLA SHS G037AX101 467,256 3,358 0.72 39,081 8.85 0.0243
2023-05-15 2023-03-31 13F AMBARELLA SHS G037AX101 463,898 7,508 1.65 35,906 -4.34 0.0237
2023-02-14 2022-12-31 13F AMBARELLA SHS G037AX101 456,390 -100,944 -18.11 37,536 19.97 0.0268
2023-01-13 2022-09-30 13F/A-1 AMBARELLA SHS G037AX101 557,334 -14,587 -2.55 31,286 -16.31 0.0234
2022-11-14 2022-09-30 13F AMBARELLA SHS G037AX101 557,334 -14,587 31,286 0.0079
2022-08-15 2022-06-30 13F AMBARELLA SHS G037AX101 571,921 16,192 2.91 37,384 -35.90 0.0258
2022-05-16 2022-03-31 13F AMBARELLA SHS G037AX101 555,729 266,922 92.42 58,318 -0.36 0.0282
2022-02-14 2021-12-31 13F AMBARELLA SHS G037AX101 288,807 -173,309 -37.50 58,531 -18.73 0.0244
2021-11-16 2021-09-30 13F AMBARELLA SHS G037AX101 462,116 -105,302 -18.56 72,023 18.96 0.0315
2021-08-16 2021-06-30 13F AMBARELLA SHS G037AX101 567,418 41,607 7.91 60,543 14.83 0.0259
2021-05-17 2021-03-31 13F AMBARELLA SHS G037AX101 525,811 -414,407 -44.08 52,723 -38.96 0.0241
2021-02-16 2020-12-31 13F AMBARELLA SHS G037AX101 940,218 -317,146 -25.22 86,368 31.63 0.0401
2020-11-16 2020-09-30 13F AMBARELLA SHS G037AX101 1,257,364 395,908 45.96 65,616 66.18 0.0342
2020-08-14 2020-06-30 13F AMBARELLA SHS G037AX101 861,456 0 0.00 39,485 -5.52 0.0222
2020-05-14 2020-03-31 13F AMBARELLA SHS G037AX101 861,456 -71,786 -7.69 41,794 -26.04 0.0288
2020-02-18 2019-12-31 13F AMBARELLA SHS G037AX101 933,242 204,353 28.04 56,512 23.39 0.0289
2019-11-14 2019-09-30 13F AMBARELLA SHS G037AX101 728,889 -37,979 -4.95 45,800 35.27 0.0248
2019-07-31 2019-06-30 13F AMBARELLA SHS G037AX101 766,868 -28,286 -3.56 33,857 -1.47 0.0184
2019-04-30 2019-03-31 13F AMBARELLA SHS G037AX101 795,154 -153,014 -16.14 34,363 3.59 0.0190
2019-02-06 2018-12-31 13F AMBARELLA SHS G037AX101 948,168 0 0.00 33,172 -9.58 0.0212
2018-11-09 2018-09-30 13F AMBARELLA SHS G037AX101 948,168 0 0.00 36,685 0.19 0.0196
2018-08-10 2018-06-30 13F AMBARELLA SHS G037AX101 948,168 133,475 16.38 36,614 -8.25 0.0209
2018-05-14 2018-03-31 13F AMBARELLA SHS G037AX101 814,693 141,211 20.97 39,908 0.85 0.0235
2018-03-12 2017-12-31 13F/A-1 AMBARELLA SHS G037AX101 673,482 673,482 39,570 0.0244
2018-02-09 2017-12-31 13F AMBARELLA SHS G037AX101 673,482 39,570 0.0244
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.