PubMatic, Inc.
US ˙ NasdaqGM ˙ US74467Q1031

SecurityPUBM / PubMatic, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership149,043 shares
Latest Disclosed Value $ 1,219,172
Citadel Advisors Llc ownership in PUBM / PubMatic, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 149,043 shares of PubMatic, Inc. (US:PUBM) valued at $1,219,172 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 266,143 shares of PubMatic, Inc.. This represents a change in shares of -44.00% during the quarter. The current value of the position is $1,696,109 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (PUBM) in the form of stock options. The firm currently holds call options representing 101,000 of underlying shares valued at $826,180 USD and put options representing 231,700 of underlying shares valued at $1,895,306 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.

PUBM / PubMatic, 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)
2026-05-15 2026-03-31 13F PUBMATIC COM CL A 74467Q103 149,043 -117,100 -44.00 1,219 -48.35 0.0002
2026-02-17 2025-12-31 13F PUBMATIC COM CL A 74467Q103 266,143 -46,985 -15.01 2,361 -8.95 0.0004
2025-11-14 2025-09-30 13F PUBMATIC COM CL A 74467Q103 313,128 -184,444 -37.07 2,593 -58.12 0.0004
2025-08-14 2025-06-30 13F PUBMATIC COM CL A 74467Q103 497,572 370,571 291.79 6,190 433.53 0.0011
2025-05-15 2025-03-31 13F PUBMATIC COM CL A 74467Q103 127,001 -36,561 -22.35 1,161 -51.71 0.0002
2025-02-14 2024-12-31 13F PUBMATIC COM CL A 74467Q103 163,562 47,389 40.79 2,403 39.09 0.0004
2024-11-14 2024-09-30 13F PUBMATIC COM CL A 74467Q103 116,173 80,318 224.01 1,727 137.23 0.0003
2024-08-14 2024-06-30 13F PUBMATIC COM CL A 74467Q103 35,855 30,850 616.38 728 516.95 0.0001
2024-05-15 2024-03-31 13F PUBMATIC COM CL A 74467Q103 5,005 4,669 1,389.58 119 2,260.00 0.0000
2024-02-14 2023-12-31 13F PUBMATIC COM CL A 74467Q103 336 -35,347 -99.06 5 -98.84 0.0000
2023-11-14 2023-09-30 13F PUBMATIC COM CL A 74467Q103 35,683 -150,736 -80.86 432 -87.35 0.0001
2023-08-14 2023-06-30 13F PUBMATIC COM CL A 74467Q103 186,419 185,954 39,990.11 3,408 56,683.33 0.0007
2023-05-15 2023-03-31 13F PUBMATIC COM CL A 74467Q103 465 -1,705 -78.57 6 -77.78 0.0000
2023-02-14 2022-12-31 13F PUBMATIC COM CL A 74467Q103 2,170 -91,025 -97.67 28 -98.26 0.0000
2022-11-14 2022-09-30 13F PUBMATIC COM CL A 74467Q103 93,195 -13,552 -12.70 1,550 -8.61 0.0004
2022-08-15 2022-06-30 13F PUBMATIC COM CL A 74467Q103 106,747 -134,408 -55.74 1,696 -73.08 0.0004
2022-05-16 2022-03-31 13F PUBMATIC COM CL A 74467Q103 241,155 -47,354 -16.41 6,299 -35.88 0.0013
2022-02-14 2021-12-31 13F PUBMATIC COM CL A 74467Q103 288,509 41,027 16.58 9,824 50.65 0.0020
2021-11-15 2021-09-30 13F PUBMATIC Cmn 74467Q103 247,482 239,804 3,123.26 6,521 2,073.67 0.0014
2021-08-16 2021-06-30 13F PUBMATIC COM CL A 74467Q103 7,678 7,678 300 0.0001
2021-05-21 2021-03-31 13F/A-1 PUBMATIC COM CL A 74467Q103 0 -141,057 -100.00 0 -100.00
2021-02-16 2020-12-31 13F PUBMATIC COM CL A 74467Q103 141,057 141,057 3,944 0.0010
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
(%)
2026-05-15 2026-03-31 13F PUBMATIC COM CL A Call 101,000 -55.90 826 -59.33 n/a n/a n/a
2026-02-17 2025-12-31 13F PUBMATIC COM CL A Call 229,000 115.63 2,031 131.06 n/a n/a n/a
2025-11-14 2025-09-30 13F PUBMATIC COM CL A Call 106,200 -19.97 879 -46.73 n/a n/a n/a
2025-08-14 2025-06-30 13F PUBMATIC COM CL A Call 132,700 12.65 1,651 53.35 n/a n/a n/a
2025-05-15 2025-03-31 13F PUBMATIC COM CL A Call 117,800 -14.64 1,077 -46.92 n/a n/a n/a
2025-02-14 2024-12-31 13F PUBMATIC COM CL A Call 138,000 -40.44 2,027 -41.16 n/a n/a n/a
2024-11-14 2024-09-30 13F PUBMATIC COM CL A Call 231,700 9.81 3,445 -19.60 n/a n/a n/a
2024-08-14 2024-06-30 13F PUBMATIC COM CL A Call 211,000 25.52 4,285 7.47 n/a n/a n/a
2024-05-15 2024-03-31 13F PUBMATIC COM CL A Call 168,100 -38.51 3,987 -10.59 n/a n/a n/a
2024-02-14 2023-12-31 13F PUBMATIC COM CL A Call 273,400 46.13 4,459 97.04 n/a n/a n/a
2023-11-14 2023-09-30 13F PUBMATIC COM CL A Call 187,100 6.67 2,264 -29.41 n/a n/a n/a
2023-08-14 2023-06-30 13F PUBMATIC COM CL A Call 175,400 -20.49 3,206 5.18 n/a n/a n/a
2023-05-15 2023-03-31 13F PUBMATIC COM CL A Call 220,600 56.56 3,049 68.96 n/a n/a n/a
2023-02-14 2022-12-31 13F PUBMATIC COM CL A Call 140,900 -11.33 1,805 -31.74 n/a n/a n/a
2022-11-14 2022-09-30 13F PUBMATIC COM CL A Call 158,900 39.51 2,643 46.02 n/a n/a n/a
2022-08-15 2022-06-30 13F PUBMATIC COM CL A Call 113,900 -28.68 1,810 -56.61 n/a n/a n/a
2022-05-16 2022-03-31 13F PUBMATIC COM CL A Call 159,700 -14.92 4,171 -34.74 n/a n/a n/a
2022-02-14 2021-12-31 13F PUBMATIC COM CL A Call 187,700 63.36 6,391 111.06 n/a n/a n/a
2021-11-15 2021-09-30 13F PUBMATIC Cmn Call 114,900 3,028 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
(%)
2026-05-15 2026-03-31 13F PUBMATIC COM CL A Put 231,700 131.70 1,895 113.64 n/a n/a n/a
2026-02-17 2025-12-31 13F PUBMATIC COM CL A Put 100,000 -5.39 887 1.37 n/a n/a n/a
2025-11-14 2025-09-30 13F PUBMATIC COM CL A Put 105,700 8.19 875 -27.98 n/a n/a n/a
2025-08-14 2025-06-30 13F PUBMATIC COM CL A Put 97,700 10.27 1,215 50.19 n/a n/a n/a
2025-05-15 2025-03-31 13F PUBMATIC COM CL A Put 88,600 -54.12 810 -71.47 n/a n/a n/a
2025-02-14 2024-12-31 13F PUBMATIC COM CL A Put 193,100 -11.18 2,837 -12.25 n/a n/a n/a
2024-11-14 2024-09-30 13F PUBMATIC COM CL A Put 217,400 46.69 3,233 7.41 n/a n/a n/a
2024-08-14 2024-06-30 13F PUBMATIC COM CL A Put 148,200 -33.12 3,010 -42.75 n/a n/a n/a
2024-05-15 2024-03-31 13F PUBMATIC COM CL A Put 221,600 81.05 5,256 163.33 n/a n/a n/a
2024-02-14 2023-12-31 13F PUBMATIC COM CL A Put 122,400 20.83 1,996 62.94 n/a n/a n/a
2023-11-14 2023-09-30 13F PUBMATIC COM CL A Put 101,300 -33.31 1,226 -55.87 n/a n/a n/a
2023-08-14 2023-06-30 13F PUBMATIC COM CL A Put 151,900 -20.22 2,777 5.51 n/a n/a n/a
2023-05-15 2023-03-31 13F PUBMATIC COM CL A Put 190,400 18.70 2,631 28.09 n/a n/a n/a
2023-02-14 2022-12-31 13F PUBMATIC COM CL A Put 160,400 28.22 2,055 -1.25 n/a n/a n/a
2022-11-14 2022-09-30 13F PUBMATIC COM CL A Put 125,100 -48.43 2,080 -46.04 n/a n/a n/a
2022-08-15 2022-06-30 13F PUBMATIC COM CL A Put 242,600 -10.48 3,855 -45.54 n/a n/a n/a
2022-05-16 2022-03-31 13F PUBMATIC COM CL A Put 271,000 -45.46 7,079 -58.16 n/a n/a n/a
2022-02-14 2021-12-31 13F PUBMATIC COM CL A Put 496,900 -19.28 16,919 4.30 n/a n/a n/a
2021-11-15 2021-09-30 13F PUBMATIC Cmn Put 615,600 16,221 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.