Ambarella, Inc.
US ˙ NasdaqGS ˙ KYG037AX1015

SecurityAMBA / Ambarella, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership30,324 shares
Latest Disclosed Value $ 1,560,928
Citigroup Inc ownership in AMBA / Ambarella, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 30,324 shares of Ambarella, Inc. (US:AMBA) valued at $1,560,928 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 30,733 shares of Ambarella, Inc.. This represents a change in shares of -1.33% during the quarter. The current value of the position is $2,237,911 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (AMBA) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

AMBA / Ambarella, Inc. Historical Put/Call Ratio
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)
2026-05-11 2026-03-31 13F AMBARELLA SHS G037AX101 30,324 -409 -1.33 1,561 -28.34 0.0003
2026-02-13 2025-12-31 13F AMBARELLA SHS G037AX101 30,733 7,799 34.01 2,177 15.06 0.0010
2025-11-10 2025-09-30 13F AMBARELLA SHS G037AX101 22,934 -25,722 -52.87 1,893 -41.13 0.0008
2025-08-11 2025-06-30 13F AMBARELLA SHS G037AX101 48,656 6,936 16.63 3,214 53.12 0.0016
2025-05-12 2025-03-31 13F AMBARELLA SHS G037AX101 41,720 -16,785 -28.69 2,100 -50.67 0.0011
2025-02-12 2024-12-31 13F AMBARELLA SHS G037AX101 58,505 4,769 8.87 4,256 40.43 0.0025
2024-11-12 2024-09-30 13F AMBARELLA SHS G037AX101 53,736 1,303 2.49 3,031 7.14 0.0018
2024-08-12 2024-06-30 13F AMBARELLA SHS G037AX101 52,433 24,157 85.43 2,829 97.07 0.0018
2024-05-10 2024-03-31 13F AMBARELLA SHS G037AX101 28,276 3,453 13.91 1,436 -5.65 0.0009
2024-02-09 2023-12-31 13F AMBARELLA SHS G037AX101 24,823 6,445 35.07 1,521 56.16 0.0011
2023-12-06 2023-09-30 13F/A-1 AMBARELLA SHS G037AX101 18,378 -5,249 -22.22 975 -50.71 0.0007
2023-11-09 2023-09-30 13F AMBARELLA SHS G037AX101 18,378 -5,249 975 0.0007
2023-08-10 2023-06-30 13F AMBARELLA SHS G037AX101 23,627 13,867 142.08 1,977 161.72 0.0013
2023-05-11 2023-03-31 13F AMBARELLA SHS G037AX101 9,760 -108 -1.09 756 -6.91 0.0005
2023-02-09 2022-12-31 13F AMBARELLA SHS G037AX101 9,868 -1,647 -14.30 811 25.54 0.0006
2022-11-10 2022-09-30 13F AMBARELLA SHS G037AX101 11,515 -863 -6.97 646 -20.25 0.0005
2022-08-10 2022-06-30 13F AMBARELLA SHS G037AX101 12,378 -22,369 -64.38 810 -77.78 0.0006
2022-05-12 2022-03-31 13F AMBARELLA SHS G037AX101 34,747 -6,311 -15.37 3,646 -56.24 0.0022
2022-02-10 2021-12-31 13F AMBARELLA SHS G037AX101 41,058 19,249 88.26 8,331 145.32 0.0045
2021-11-10 2021-09-30 13F AMBARELLA SHS G037AX101 21,809 -6,350 -22.55 3,396 13.12 0.0020
2021-08-10 2021-06-30 13F AMBARELLA SHS G037AX101 28,159 5,442 23.96 3,002 31.67 0.0018
2021-05-13 2021-03-31 13F AMBARELLA SHS G037AX101 22,717 -14,240 -38.53 2,280 -32.82 0.0015
2021-02-11 2020-12-31 13F AMBARELLA SHS G037AX101 36,957 22,605 157.50 3,394 352.53 0.0020
2020-11-12 2020-09-30 13F AMBARELLA SHS G037AX101 14,352 -21,517 -59.99 750 -54.32 0.0005
2020-08-12 2020-06-30 13F AMBARELLA SHS G037AX101 35,869 4,630 14.82 1,642 8.17 0.0013
2020-05-12 2020-03-31 13F AMBARELLA SHS G037AX101 31,239 15,439 97.72 1,518 58.79 0.0014
2020-02-12 2019-12-31 13F AMBARELLA SHS G037AX101 15,800 -1,391 -8.09 956 -11.56 0.0007
2019-11-08 2019-09-30 13F AMBARELLA SHS G037AX101 17,191 -8,190 -32.27 1,081 -3.48 0.0009
2019-08-12 2019-06-30 13F AMBARELLA SHS G037AX101 25,381 20,876 463.40 1,120 477.32 0.0009
2019-05-13 2019-03-31 13F AMBARELLA SHS G037AX101 4,505 -19,662 -81.36 194 -77.07 0.0002
2019-02-12 2018-12-31 13F AMBARELLA SHS G037AX101 24,167 22,748 1,603.10 846 1,438.18 0.0009
2018-11-13 2018-09-30 13F AMBARELLA SHS G037AX101 1,419 -21,044 -93.68 55 -93.66 0.0000
2018-08-10 2018-06-30 13F AMBARELLA SHS G037AX101 22,463 -10,317 -31.47 868 -45.95 0.0008
2018-05-11 2018-03-31 13F AMBARELLA SHS G037AX101 32,780 20,630 169.79 1,606 124.93 0.0013
2018-02-12 2017-12-31 13F AMBARELLA SHS G037AX101 12,150 -297,603 -96.08 714 -95.30 0.0006
2017-11-13 2017-09-30 13F AMBARELLA SHS G037AX101 309,753 294,632 1,948.50 15,181 1,965.44 0.0124
2017-08-11 2017-06-30 13F AMBARELLA SHS G037AX101 15,121 -211 -1.38 735 -12.40 0.0007
2017-05-12 2017-03-31 13F AMBARELLA SHS G037AX101 15,332 -24,302 -61.32 839 -60.89 0.0007
2017-02-10 2016-12-31 13F AMBARELLA SHS G037AX101 39,634 31,906 412.86 2,145 276.98 0.0019
2016-11-10 2016-09-30 13F AMBARELLA SHS G037AX101 7,728 -7,337 -48.70 569 -25.62 0.0005
2016-08-12 2016-06-30 13F AMBARELLA SHS G037AX101 15,065 -22,410 -59.80 765 -54.33 0.0008
2016-05-13 2016-03-31 13F AMBARELLA SHS G037AX101 37,475 18,024 92.66 1,675 54.52 0.0019
2016-02-12 2015-12-31 13F AMBARELLA SHS G037AX101 19,451 7,436 61.89 1,084 56.20 0.0011
2015-11-13 2015-09-30 13F AMBARELLA SHS G037AX101 12,015 -25,386 -67.88 694 -81.93 0.0006
2015-08-13 2015-06-30 13F AMBARELLA SHS G037AX101 37,401 23,079 161.14 3,841 254.01 0.0034
2015-05-14 2015-03-31 13F AMBARELLA SHS G037AX101 14,322 5,628 64.73 1,085 146.03 0.0010
2015-02-17 2014-12-31 13F AMBARELLA SHS G037AX101 8,694 6,228 252.55 441 308.33 0.0004
2014-11-14 2014-09-30 13F AMBARELLA SHS G037AX101 2,466 1,118 82.94 108 157.14 0.0001
2014-08-14 2014-06-30 13F AMBARELLA SHS G037AX101 1,348 -3,070 -69.49 42 -64.41 0.0000
2014-05-15 2014-03-31 13F AMBARELLA SHS G037AX101 4,418 -5,400 -55.00 118 -64.56 0.0001
2014-02-14 2013-12-31 13F AMBARELLA SHS G037AX101 9,818 8,584 695.62 333 1,287.50 0.0003
2013-11-14 2013-09-30 13F AMBARELLA SHS G037AX101 1,234 -1,924 -60.92 24 -54.72 0.0000
2013-08-14 2013-06-30 13F AMBARELLA SHS G037AX101 3,158 3,158 53 0.0001
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2021-05-13 2021-03-31 13F AMBARELLA SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F AMBARELLA SHS Call 23,600 -32.57 2,167 18.67 n/a n/a n/a
2020-11-12 2020-09-30 13F AMBARELLA SHS Call 35,000 65.09 1,826 88.05 n/a n/a n/a
2020-08-12 2020-06-30 13F AMBARELLA SHS Call 21,200 -47.00 971 -50.00 n/a n/a n/a
2020-05-12 2020-03-31 13F AMBARELLA SHS Call 40,000 -32.09 1,942 -45.56 n/a n/a n/a
2020-02-12 2019-12-31 13F AMBARELLA SHS Call 58,900 14.81 3,567 10.67 n/a n/a n/a
2019-11-08 2019-09-30 13F AMBARELLA SHS Call 51,300 -0.19 3,223 42.11 n/a n/a n/a
2019-08-12 2019-06-30 13F AMBARELLA SHS Call 51,400 15.25 2,268 17.70 n/a n/a n/a
2019-05-13 2019-03-31 13F AMBARELLA SHS Call 44,600 -31.70 1,927 -15.63 n/a n/a n/a
2019-02-12 2018-12-31 13F AMBARELLA SHS Call 65,300 -48.50 2,284 -53.44 n/a n/a n/a
2018-11-13 2018-09-30 13F AMBARELLA SHS Call 126,800 8.56 4,905 8.76 n/a n/a n/a
2018-08-10 2018-06-30 13F AMBARELLA SHS Call 116,800 2.01 4,510 -19.59 n/a n/a n/a
2018-05-11 2018-03-31 13F AMBARELLA SHS Call 114,500 17.32 5,609 -2.18 n/a n/a n/a
2018-02-12 2017-12-31 13F AMBARELLA SHS Call 97,600 154.17 5,734 204.68 n/a n/a n/a
2017-11-13 2017-09-30 13F AMBARELLA SHS Call 38,400 11.63 1,882 12.69 n/a n/a n/a
2017-08-11 2017-06-30 13F AMBARELLA SHS Call 34,400 262.11 1,670 221.15 n/a n/a n/a
2017-05-12 2017-03-31 13F AMBARELLA SHS Call 9,500 -53.43 520 -52.90 n/a n/a n/a
2017-02-10 2016-12-31 13F AMBARELLA SHS Call 20,400 -35.24 1,104 -52.39 n/a n/a n/a
2016-11-10 2016-09-30 13F AMBARELLA SHS Call 31,500 52.17 2,319 120.44 n/a n/a n/a
2016-08-12 2016-06-30 13F AMBARELLA SHS Call 20,700 -41.36 1,052 -33.33 n/a n/a n/a
2016-05-13 2016-03-31 13F AMBARELLA SHS Call 35,300 -4.59 1,578 -23.47 n/a n/a n/a
2016-02-12 2015-12-31 13F AMBARELLA SHS Call 37,000 -44.36 2,062 -46.34 n/a n/a n/a
2015-11-13 2015-09-30 13F AMBARELLA SHS Call 66,500 -2.78 3,843 -45.29 n/a n/a n/a
2015-08-13 2015-06-30 13F AMBARELLA SHS Call 68,400 286.44 7,024 424.18 n/a n/a n/a
2015-05-14 2015-03-31 13F AMBARELLA SHS Call 17,700 47.50 1,340 120.03 n/a n/a n/a
2015-02-17 2014-12-31 13F AMBARELLA SHS Call 12,000 609 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2021-05-13 2021-03-31 13F AMBARELLA SHS Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F AMBARELLA SHS Put 50,700 -15.92 4,655 47.97 n/a n/a n/a
2020-11-12 2020-09-30 13F AMBARELLA SHS Put 60,300 -5.93 3,146 7.15 n/a n/a n/a
2020-08-12 2020-06-30 13F AMBARELLA SHS Put 64,100 15.29 2,936 8.74 n/a n/a n/a
2020-05-12 2020-03-31 13F AMBARELLA SHS Put 55,600 7.96 2,700 -13.43 n/a n/a n/a
2020-02-12 2019-12-31 13F AMBARELLA SHS Put 51,500 17.58 3,119 13.34 n/a n/a n/a
2019-11-08 2019-09-30 13F AMBARELLA SHS Put 43,800 -20.36 2,752 13.39 n/a n/a n/a
2019-08-12 2019-06-30 13F AMBARELLA SHS Put 55,000 2.80 2,427 5.02 n/a n/a n/a
2019-05-13 2019-03-31 13F AMBARELLA SHS Put 53,500 -24.44 2,311 -6.70 n/a n/a n/a
2019-02-12 2018-12-31 13F AMBARELLA SHS Put 70,800 -10.49 2,477 -19.05 n/a n/a n/a
2018-11-13 2018-09-30 13F AMBARELLA SHS Put 79,100 -21.92 3,060 -21.76 n/a n/a n/a
2018-08-10 2018-06-30 13F AMBARELLA SHS Put 101,300 -26.96 3,911 -42.44 n/a n/a n/a
2018-05-11 2018-03-31 13F AMBARELLA SHS Put 138,700 81.31 6,795 51.20 n/a n/a n/a
2018-02-12 2017-12-31 13F AMBARELLA SHS Put 76,500 220.08 4,494 283.77 n/a n/a n/a
2017-11-13 2017-09-30 13F AMBARELLA SHS Put 23,900 7.17 1,171 8.13 n/a n/a n/a
2017-08-11 2017-06-30 13F AMBARELLA SHS Put 22,300 277.97 1,083 235.29 n/a n/a n/a
2017-05-12 2017-03-31 13F AMBARELLA SHS Put 5,900 -76.68 323 -76.41 n/a n/a n/a
2017-02-10 2016-12-31 13F AMBARELLA SHS Put 25,300 -18.91 1,369 -40.40 n/a n/a n/a
2016-11-10 2016-09-30 13F AMBARELLA SHS Put 31,200 44.44 2,297 109.39 n/a n/a n/a
2016-08-12 2016-06-30 13F AMBARELLA SHS Put 21,600 -6.49 1,097 6.20 n/a n/a n/a
2016-05-13 2016-03-31 13F AMBARELLA SHS Put 23,100 -40.46 1,033 -52.24 n/a n/a n/a
2016-02-12 2015-12-31 13F AMBARELLA SHS Put 38,800 -37.01 2,163 -39.24 n/a n/a n/a
2015-11-13 2015-09-30 13F AMBARELLA SHS Put 61,600 -46.67 3,560 -69.99 n/a n/a n/a
2015-08-13 2015-06-30 13F AMBARELLA SHS Put 115,500 329.37 11,861 482.28 n/a n/a n/a
2015-05-14 2015-03-31 13F AMBARELLA SHS Put 26,900 497.78 2,037 793.42 n/a n/a n/a
2015-02-17 2014-12-31 13F AMBARELLA SHS Put 4,500 228 n/a n/a n/a
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.