PDF Solutions, Inc.
US ˙ NasdaqGS ˙ US6932821050

SecurityPDFS / PDF Solutions, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in PDFS / PDF Solutions, Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of PDF Solutions, Inc. (US:PDFS) valued at $0 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 540 shares of PDF Solutions, Inc.. The current value of the position is $0 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (PDFS) in the form of stock options. The firm currently holds call options representing 200 of underlying shares valued at $6,542 USD and put options representing 300 of underlying shares valued at $9,813 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.

PDFS / PDF Solutions, 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)
2026-05-14 2026-03-31 13F PDF SOLUTIONS COM 693282105 0 -100.00 0
2026-02-11 2025-12-31 13F PDF SOLUTIONS COM 693282105 540 540 15 0.0000
2025-11-12 2025-09-30 13F PDF SOLUTIONS COM 693282105 0 -198 -100.00 0 0.0000
2025-08-05 2025-06-30 13F PDF SOLUTIONS COM 693282105 198 89 81.65 0 0.0000
2025-05-12 2025-03-31 13F PDF SOLUTIONS COM 693282105 109 -4,534 -97.65 0 0.0000
2025-02-11 2024-12-31 13F PDF SOLUTIONS COM 693282105 4,643 4,643 0 0.0001
2024-11-08 2024-09-30 13F PDF SOLUTIONS COM 693282105 0 -308 -100.00 0 0.0000
2024-07-25 2024-06-30 13F PDF SOLUTIONS COM 693282105 308 -3,179 -91.17 0 0.0000
2024-04-25 2024-03-31 13F PDF SOLUTIONS COM 693282105 3,487 3,487 0 0.0001
2023-02-02 2022-12-31 13F PDF SOLUTIONS COM 693282105 0 -248 -100.00 0 -100.00
2022-11-04 2022-09-30 13F PDF SOLUTIONS COM 693282105 248 248 6 0.0000
2022-08-03 2022-06-30 13F PDF SOLUTIONS COM 693282105 0 -1,656 -100.00 0 -100.00
2022-05-02 2022-03-31 13F PDF SOLUTIONS COM 693282105 1,656 -3,847 -69.91 46 -73.56 0.0000
2022-02-23 2021-12-31 13F/A-1 PDF SOLUTIONS COM 693282105 5,503 5,129 1,371.39 174 2,800.00 0.0002
2022-02-04 2021-12-31 13F PDF SOLUTIONS COM 693282105 374 0 6 0.0000
2021-10-28 2021-09-30 13F PDF SOLUTIONS COM 693282105 374 0 0.00 6 0.00 0.0000
2021-08-12 2021-06-30 13F PDF SOLUTIONS COM 693282105 374 374 6 0.0000
2020-10-14 2020-09-30 13F PDF SOLUTIONS COM 693282105 0 -1,788 -100.00 0 -100.00
2020-07-13 2020-06-30 13F PDF SOLUTIONS COM 693282105 1,788 1,724 2,693.75 34 0.0001
2020-04-29 2020-03-31 13F PDF SOLUTIONS COM 693282105 64 64 -96.42 0 -100.00 0.0000
2020-02-05 2019-12-31 13F PDF SOLUTIONS COM 693282105 0 -24,710 -100.00 0 -100.00
2019-10-15 2019-09-30 13F PDF SOLUTIONS COM 693282105 24,710 -7,313 -22.84 322 -23.33 0.0009
2019-07-26 2019-06-30 13F PDF SOLUTIONS COM 693282105 32,023 -30,102 -48.45 420 -45.24 0.0011
2019-04-18 2019-03-31 13F PDF SOLUTIONS COM 693282105 62,125 29,664 91.38 767 180.95 0.0021
2019-01-16 2018-12-31 13F PDF SOLUTIONS COM 693282105 32,461 -24,548 -43.06 273 -46.89 0.0008
2018-10-23 2018-09-30 13F PDF SOLUTIONS COM 693282105 57,009 53,964 1,772.22 514 1,327.78 0.0017
2018-07-30 2018-06-30 13F PDF SOLUTIONS COM 693282105 3,045 3,045 -94.66 36 -93.00 0.0001
2018-04-26 2018-03-31 13F PDF SOLUTIONS COM 693282105 0 -704 -100.00 0 -100.00
2018-01-10 2017-12-31 13F PDF SOLUTIONS COM 693282105 704 610 648.94 11 1,000.00 0.0005
2017-10-25 2017-09-30 13F PDF SOLUTIONS COM 693282105 94 -93 -49.73 1 -66.67 0.0000
2017-07-12 2017-06-30 13F PDF SOLUTIONS COM 693282105 187 187 3 0.0001
2016-04-14 2016-03-31 13F PDF SOLUTIONS COM 693282105 0 -400 -100.00 0 -100.00
2016-01-20 2015-12-31 13F PDF SOLUTIONS COM 693282105 400 319 393.83 4 0.0003
2015-10-08 2015-09-30 13F PDF SOLUTIONS COM 693282105 81 81 -79.75 0 -100.00 0.0000
2015-07-08 2015-06-30 13F PDF SOLUTIONS COM 693282105 0 -89 -100.00 0 -100.00
2015-04-21 2015-03-31 13F PDF SOLUTIONS COM 693282105 89 89 1 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
(%)
2026-05-14 2026-03-31 13F PDF SOLUTIONS CALL Call 200 -33.33 7 -25.00 n/a n/a n/a
2026-02-11 2025-12-31 13F PDF SOLUTIONS CALL Call 300 -96.51 9 n/a n/a n/a
2025-11-12 2025-09-30 13F PDF SOLUTIONS CALL Call 8,600 0 n/a n/a n/a
2024-02-02 2023-12-31 13F PDF SOLUTIONS CALL Call 0 -100.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F PDF SOLUTIONS CALL Call 400 0.00 0 n/a n/a n/a
2023-08-04 2023-06-30 13F PDF SOLUTIONS CALL Call 400 0 n/a n/a n/a
2022-08-03 2022-06-30 13F PDF SOLUTIONS CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-02 2022-03-31 13F PDF SOLUTIONS CALL Call 100 2 n/a n/a n/a
2020-10-14 2020-09-30 13F PDF SOLUTIONS CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-07-13 2020-06-30 13F PDF SOLUTIONS CALL Call 3 200.00 5 400.00 n/a n/a n/a
2020-04-29 2020-03-31 13F PDF SOLUTIONS CALL Call 1 1 n/a n/a n/a
2019-07-26 2019-06-30 13F PDF SOLUTIONS CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-04-18 2019-03-31 13F PDF SOLUTIONS CALL Call 1 0.00 1 n/a n/a n/a
2019-01-16 2018-12-31 13F PDF SOLUTIONS CALL Call 1 -83.33 0 -100.00 n/a n/a n/a
2018-10-23 2018-09-30 13F PDF SOLUTIONS CALL Call 6 0.00 5 -28.57 n/a n/a n/a
2018-07-30 2018-06-30 13F PDF SOLUTIONS CALL Call 6 0.00 7 40.00 n/a n/a n/a
2018-01-10 2017-12-31 13F PDF SOLUTIONS CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-10-25 2017-09-30 13F PDF SOLUTIONS CALL Call 5 -28.57 0 n/a n/a n/a
2017-07-12 2017-06-30 13F PDF SOLUTIONS CALL Call 7 -80.00 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F PDF SOLUTIONS CALL Call 35 9.38 4 -42.86 n/a n/a n/a
2017-01-11 2016-12-31 13F PDF SOLUTIONS CALL Call 32 7 n/a n/a n/a
2016-07-18 2016-06-30 13F PDF SOLUTIONS CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-04-14 2016-03-31 13F PDF SOLUTIONS CALL Call 1 0 n/a n/a n/a
2015-04-21 2015-03-31 13F PDF SOLUTIONS CALL Call 0 -100.00 0 n/a n/a n/a
2015-03-04 2014-12-31 13F PDF SOLUTIONS CALL Call 17 0 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
(%)
2026-05-14 2026-03-31 13F PDF SOLUTIONS PUT Put 300 -57.14 10 -52.63 n/a n/a n/a
2026-02-11 2025-12-31 13F PDF SOLUTIONS PUT Put 700 20 n/a n/a n/a
2025-05-12 2025-03-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 n/a n/a n/a
2025-02-11 2024-12-31 13F PDF SOLUTIONS PUT Put 6,000 0 n/a n/a n/a
2023-02-02 2022-12-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F PDF SOLUTIONS PUT Put 200 4 n/a n/a n/a
2022-05-02 2022-03-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-23 2021-12-31 13F/A PDF SOLUTIONS PUT Put 900 28 n/a n/a n/a
2021-02-02 2020-12-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-10-14 2020-09-30 13F PDF SOLUTIONS PUT Put 12 300.00 22 340.00 n/a n/a n/a
2020-07-13 2020-06-30 13F PDF SOLUTIONS PUT Put 3 -75.00 5 -77.27 n/a n/a n/a
2020-04-28 2020-03-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-05 2019-12-31 13F PDF SOLUTIONS PUT Put 1 -99.78 1 -99.83 n/a n/a n/a
2019-10-15 2019-09-30 13F PDF SOLUTIONS PUT Put 445 -2.63 581 -3.01 n/a n/a n/a
2019-07-26 2019-06-30 13F PDF SOLUTIONS PUT Put 457 158.19 599 174.77 n/a n/a n/a
2019-04-18 2019-03-31 13F PDF SOLUTIONS PUT Put 177 -60.58 218 -42.33 n/a n/a n/a
2019-01-16 2018-12-31 13F PDF SOLUTIONS PUT Put 449 -43.52 378 -47.28 n/a n/a n/a
2018-10-23 2018-09-30 13F PDF SOLUTIONS PUT Put 795 3,212.50 717 2,460.71 n/a n/a n/a
2018-07-30 2018-06-30 13F PDF SOLUTIONS PUT Put 24 -96.98 28 -96.09 n/a n/a n/a
2018-04-26 2018-03-31 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F PDF SOLUTIONS PUT Put 4 1 n/a n/a n/a
2017-10-25 2017-09-30 13F PDF SOLUTIONS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-07-12 2017-06-30 13F PDF SOLUTIONS PUT Put 7 -86.00 1 n/a n/a n/a
2017-04-21 2017-03-31 13F PDF SOLUTIONS PUT Put 50 0 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.