Eton Pharmaceuticals, Inc.
US ˙ NasdaqGM ˙ US29772L1089

SecurityETON / Eton Pharmaceuticals, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in ETON / Eton Pharmaceuticals, Inc.

On August 5, 2025 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of Eton Pharmaceuticals, Inc. (US:ETON) valued at $0 USD as of June 30, 2025. The entity filed a previous 13F-HR on May 12, 2025 disclosing 4,472 shares of Eton Pharmaceuticals, 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 (ETON) in the form of stock options. The firm currently holds call options representing 31,200 of underlying shares valued at $770,016 USD and put options representing 19,500 of underlying shares valued at $481,260 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.

ETON / Eton Pharmaceuticals, 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)
2025-08-05 2025-06-30 13F ETON PHARMACEUTICALS COM 29772L108 0 -4,472 -100.00 0 0.0000
2025-05-12 2025-03-31 13F ETON PHARMACEUTICALS COM 29772L108 4,472 -31,904 -87.71 0 0.0000
2025-02-11 2024-12-31 13F ETON PHARMACEUTICALS COM 29772L108 36,376 36,376 0 0.0003
2022-05-02 2022-03-31 13F ETON PHARMACEUTICALS COM 29772L108 0 -22,642 -100.00 0 -100.00
2022-02-23 2021-12-31 13F/A-1 ETON PHARMACEUTICALS COM 29772L108 22,642 17,406 332.43 97 203.13 0.0001
2022-02-04 2021-12-31 13F ETON PHARMACEUTICALS COM 29772L108 5,236 0 32 0.0000
2021-10-28 2021-09-30 13F ETON PHARMACEUTICALS COM 29772L108 5,236 0 0.00 32 0.00 0.0000
2021-08-12 2021-06-30 13F ETON PHARMACEUTICALS COM 29772L108 5,236 4,136 376.00 32 300.00 0.0000
2021-04-26 2021-03-31 13F ETON PHARMACEUTICALS COM 29772L108 1,100 1,100 8 0.0000
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 ETON PHARMACEUTICALS CALL Call 31,200 290.00 770 470.37 n/a n/a n/a
2026-02-11 2025-12-31 13F ETON PHARMACEUTICALS CALL Call 8,000 2.56 135 n/a n/a n/a
2025-11-12 2025-09-30 13F ETON PHARMACEUTICALS CALL Call 7,800 -80.10 0 n/a n/a n/a
2025-08-05 2025-06-30 13F ETON PHARMACEUTICALS CALL Call 39,200 716.67 1 n/a n/a n/a
2025-05-12 2025-03-31 13F ETON PHARMACEUTICALS CALL Call 4,800 -17.24 0 n/a n/a n/a
2025-02-11 2024-12-31 13F ETON PHARMACEUTICALS CALL Call 5,800 -38.95 0 n/a n/a n/a
2024-11-08 2024-09-30 13F ETON PHARMACEUTICALS CALL Call 9,500 7.95 0 n/a n/a n/a
2024-07-25 2024-06-30 13F ETON PHARMACEUTICALS CALL Call 8,800 91.30 0 n/a n/a n/a
2024-04-25 2024-03-31 13F ETON PHARMACEUTICALS CALL Call 4,600 -2.13 0 n/a n/a n/a
2024-02-02 2023-12-31 13F ETON PHARMACEUTICALS CALL Call 4,700 -58.04 0 n/a n/a n/a
2023-11-01 2023-09-30 13F ETON PHARMACEUTICALS CALL Call 11,200 -25.33 0 n/a n/a n/a
2023-08-04 2023-06-30 13F ETON PHARMACEUTICALS CALL Call 15,000 68.54 0 n/a n/a n/a
2023-04-27 2023-03-31 13F ETON PHARMACEUTICALS CALL Call 8,900 -82.48 0 n/a n/a n/a
2023-02-02 2022-12-31 13F ETON PHARMACEUTICALS CALL Call 50,800 -2.68 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ETON PHARMACEUTICALS CALL Call 52,200 -45.11 109 -56.22 n/a n/a n/a
2022-08-03 2022-06-30 13F ETON PHARMACEUTICALS CALL Call 95,100 19.32 249 -28.24 n/a n/a n/a
2022-05-02 2022-03-31 13F ETON PHARMACEUTICALS CALL Call 79,700 279.52 347 285.56 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ETON PHARMACEUTICALS CALL Call 21,000 110.00 90 45.16 n/a n/a n/a
2022-02-04 2021-12-31 13F ETON PHARMACEUTICALS CALL Call 10,000 62 n/a n/a n/a
2021-10-28 2021-09-30 13F ETON PHARMACEUTICALS CALL Call 10,000 0.00 62 1.64 n/a n/a n/a
2021-08-12 2021-06-30 13F ETON PHARMACEUTICALS CALL Call 10,000 61 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 ETON PHARMACEUTICALS PUT Put 19,500 9,650.00 481 15,933.33 n/a n/a n/a
2026-02-11 2025-12-31 13F ETON PHARMACEUTICALS PUT Put 200 -98.41 3 n/a n/a n/a
2025-11-12 2025-09-30 13F ETON PHARMACEUTICALS PUT Put 12,600 0 n/a n/a n/a
2025-08-05 2025-06-30 13F ETON PHARMACEUTICALS PUT Put 0 -100.00 0 n/a n/a n/a
2025-05-12 2025-03-31 13F ETON PHARMACEUTICALS PUT Put 3,600 0 n/a n/a n/a
2024-02-02 2023-12-31 13F ETON PHARMACEUTICALS PUT Put 0 -100.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F ETON PHARMACEUTICALS PUT Put 100 0 n/a n/a n/a
2022-11-04 2022-09-30 13F ETON PHARMACEUTICALS PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-08-03 2022-06-30 13F ETON PHARMACEUTICALS PUT Put 2,500 -56.90 6 -76.00 n/a n/a n/a
2022-05-02 2022-03-31 13F ETON PHARMACEUTICALS PUT Put 5,800 1.75 25 4.17 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ETON PHARMACEUTICALS PUT Put 5,700 -1.72 24 -33.33 n/a n/a n/a
2022-02-04 2021-12-31 13F ETON PHARMACEUTICALS PUT Put 5,800 36 n/a n/a n/a
2021-10-28 2021-09-30 13F ETON PHARMACEUTICALS PUT Put 5,800 0.00 36 2.86 n/a n/a n/a
2021-08-12 2021-06-30 13F ETON PHARMACEUTICALS PUT Put 5,800 7,633.33 35 -35.19 n/a n/a n/a
2021-04-26 2021-03-31 13F ETON PHARMACEUTICALS PUT Put 75 54 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.