Ardelyx, Inc.
US ˙ NasdaqGM ˙ US0396971071

SecurityARDX / Ardelyx, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership174,861 shares
Latest Disclosed Value $ 1,047,417
Simplex Trading, Llc ownership in ARDX / Ardelyx, Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 174,861 shares of Ardelyx, Inc. (US:ARDX) valued at $1,047,417 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 151,934 shares of Ardelyx, Inc.. This represents a change in shares of 15.09% during the quarter. The current value of the position is $947,747 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (ARDX) in the form of stock options. The firm currently holds call options representing 109,200 of underlying shares valued at $654,108 USD and put options representing 59,900 of underlying shares valued at $358,801 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.

ARDX / Ardelyx, 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 ARDELYX COM 039697107 174,861 22,927 15.09 1,047 18.31 0.0003
2026-02-11 2025-12-31 13F ARDELYX COM 039697107 151,934 -57,299 -27.39 886 88,400.00 0.0005
2025-11-12 2025-09-30 13F ARDELYX COM 039697107 209,233 79,552 61.34 1 0.0006
2025-08-05 2025-06-30 13F ARDELYX COM 039697107 129,681 -213,693 -62.23 1 -100.00 0.0003
2025-05-12 2025-03-31 13F ARDELYX COM 039697107 343,374 173,511 102.15 2 0.0011
2025-02-11 2024-12-31 13F ARDELYX COM 039697107 169,863 -70,336 -29.28 1 -100.00 0.0005
2024-11-08 2024-09-30 13F ARDELYX COM 039697107 240,199 -72,798 -23.26 2 -50.00 0.0010
2024-07-25 2024-06-30 13F ARDELYX COM 039697107 312,997 170,348 119.42 2 100.00 0.0014
2024-04-25 2024-03-31 13F ARDELYX COM 039697107 142,649 -258,030 -64.40 1 -50.00 0.0006
2024-02-02 2023-12-31 13F ARDELYX COM 039697107 400,679 245,708 158.55 2 0.0016
2023-11-01 2023-09-30 13F ARDELYX COM 039697107 154,971 58,031 59.86 1 0.0005
2023-08-04 2023-06-30 13F ARDELYX COM 039697107 96,940 96,940 0 0.0003
2023-04-27 2023-03-31 13F ARDELYX COM 039697107 0 -85,055 -100.00 0 0.0000
2023-02-02 2022-12-31 13F ARDELYX COM 039697107 85,055 -79,506 -48.31 0 -100.00 0.0003
2022-11-04 2022-09-30 13F ARDELYX COM 039697107 164,561 -299,383 -64.53 195 -28.57 0.0002
2022-08-03 2022-06-30 13F ARDELYX COM 039697107 463,944 213,352 85.14 273 1.87 0.0003
2022-05-02 2022-03-31 13F ARDELYX COM 039697107 250,592 44,928 21.85 268 18.58 0.0002
2022-02-23 2021-12-31 13F/A-1 ARDELYX COM 039697107 205,664 178,643 661.13 226 5.61 0.0002
2022-02-04 2021-12-31 13F ARDELYX COM 039697107 27,021 0 214 0.0002
2021-10-28 2021-09-30 13F ARDELYX COM 039697107 27,021 10,127 59.94 214 67.19 0.0002
2021-08-12 2021-06-30 13F ARDELYX COM 039697107 16,894 6,281 59.18 128 82.86 0.0001
2021-04-26 2021-03-31 13F ARDELYX COM 039697107 10,613 -37,592 -77.98 70 -77.49 0.0001
2021-02-02 2020-12-31 13F ARDELYX COM 039697107 48,205 48,205 354.21 311 344.29 0.0004
2020-10-14 2020-09-30 13F ARDELYX COM 039697107 0 -3,868 -100.00 0 -100.00
2020-07-13 2020-06-30 13F ARDELYX COM 039697107 3,868 -8,254 -68.09 26 -61.76 0.0000
2020-04-29 2020-03-31 13F ARDELYX COM 039697107 12,122 -15,817 -56.61 68 -67.46 0.0001
2020-02-05 2019-12-31 13F ARDELYX COM 039697107 27,939 27,939 130.48 209 207.35 0.0005
2019-04-18 2019-03-31 13F ARDELYX COM 039697107 0 -2,022 -100.00 0 -100.00
2019-01-16 2018-12-31 13F ARDELYX COM 039697107 2,022 2,022 3 0.0000
2018-10-23 2018-09-30 13F ARDELYX COM 039697107 0 -1,933 -100.00 0 -100.00
2018-07-30 2018-06-30 13F ARDELYX COM 039697107 1,933 1,832 1,813.86 7 0.0000
2018-04-26 2018-03-31 13F ARDELYX COM 039697107 101 -6,213 -98.40 0 -100.00
2018-01-10 2017-12-31 13F ARDELYX COM 039697107 6,314 1,337 26.86 41 51.85 0.0018
2017-10-25 2017-09-30 13F ARDELYX COM 039697107 4,977 2,802 128.83 27 145.45 0.0011
2017-07-12 2017-06-30 13F ARDELYX COM 039697107 2,175 2,175 11 0.0005
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 ARDELYX CALL Call 109,200 112.45 654 118.73 n/a n/a n/a
2026-02-11 2025-12-31 13F ARDELYX CALL Call 51,400 -18.93 300 n/a n/a n/a
2025-11-12 2025-09-30 13F ARDELYX CALL Call 63,400 25.30 0 n/a n/a n/a
2025-08-05 2025-06-30 13F ARDELYX CALL Call 50,600 -42.95 0 n/a n/a n/a
2025-05-12 2025-03-31 13F ARDELYX CALL Call 88,700 -64.22 0 -100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F ARDELYX CALL Call 247,900 -17.97 1 -50.00 n/a n/a n/a
2024-11-08 2024-09-30 13F ARDELYX CALL Call 302,200 -8.15 2 0.00 n/a n/a n/a
2024-07-25 2024-06-30 13F ARDELYX CALL Call 329,000 -6.24 2 0.00 n/a n/a n/a
2024-04-25 2024-03-31 13F ARDELYX CALL Call 350,900 12.72 3 100.00 n/a n/a n/a
2024-02-02 2023-12-31 13F ARDELYX CALL Call 311,300 66.20 2 n/a n/a n/a
2023-11-01 2023-09-30 13F ARDELYX CALL Call 187,300 6.85 1 n/a n/a n/a
2023-08-04 2023-06-30 13F ARDELYX CALL Call 175,300 -40.33 1 -100.00 n/a n/a n/a
2023-04-27 2023-03-31 13F ARDELYX CALL Call 293,800 -26.09 1 0.00 n/a n/a n/a
2023-02-02 2022-12-31 13F ARDELYX CALL Call 397,500 43.55 1 -99.70 n/a n/a n/a
2022-11-04 2022-09-30 13F ARDELYX CALL Call 276,900 87.73 329 278.16 n/a n/a n/a
2022-08-03 2022-06-30 13F ARDELYX CALL Call 147,500 -50.90 87 -72.90 n/a n/a n/a
2022-05-02 2022-03-31 13F ARDELYX CALL Call 300,400 84.07 321 79.33 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ARDELYX CALL Call 163,200 101.73 179 -72.16 n/a n/a n/a
2022-02-04 2021-12-31 13F ARDELYX CALL Call 80,900 643 n/a n/a n/a
2021-10-28 2021-09-30 13F ARDELYX CALL Call 80,900 -11.78 643 -7.48 n/a n/a n/a
2021-08-12 2021-06-30 13F ARDELYX CALL Call 91,700 118,990.91 695 1,290.00 n/a n/a n/a
2021-04-26 2021-03-31 13F ARDELYX CALL Call 77 83.33 50 85.19 n/a n/a n/a
2021-02-02 2020-12-31 13F ARDELYX CALL Call 42 -68.18 27 -60.87 n/a n/a n/a
2020-10-14 2020-09-30 13F ARDELYX CALL Call 132 -1.49 69 -25.00 n/a n/a n/a
2020-07-13 2020-06-30 13F ARDELYX CALL Call 134 1,575.00 92 2,200.00 n/a n/a n/a
2020-04-29 2020-03-31 13F ARDELYX CALL Call 8 -97.05 4 -98.03 n/a n/a n/a
2020-02-05 2019-12-31 13F ARDELYX CALL Call 271 83.11 203 194.20 n/a n/a n/a
2019-10-15 2019-09-30 13F ARDELYX CALL Call 148 2,014.29 69 6,800.00 n/a n/a n/a
2019-07-26 2019-06-30 13F ARDELYX CALL Call 7 -95.27 1 -98.55 n/a n/a n/a
2019-04-18 2019-03-31 13F ARDELYX CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-01-16 2018-12-31 13F ARDELYX CALL Call 4 -20.00 0 -100.00 n/a n/a n/a
2018-10-23 2018-09-30 13F ARDELYX CALL Call 5 -44.44 2 -33.33 n/a n/a n/a
2018-07-30 2018-06-30 13F ARDELYX CALL Call 9 80.00 3 50.00 n/a n/a n/a
2018-04-26 2018-03-31 13F ARDELYX CALL Call 5 25.00 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F ARDELYX CALL Call 4 -80.00 1 -83.33 n/a n/a n/a
2017-10-25 2017-09-30 13F ARDELYX CALL Call 20 566.67 6 500.00 n/a n/a n/a
2017-07-12 2017-06-30 13F ARDELYX CALL Call 3 200.00 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F ARDELYX CALL Call 1 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 ARDELYX PUT Put 59,900 195.07 359 203.39 n/a n/a n/a
2026-02-11 2025-12-31 13F ARDELYX PUT Put 20,300 -24.54 118 n/a n/a n/a
2025-11-12 2025-09-30 13F ARDELYX PUT Put 26,900 -7.56 0 n/a n/a n/a
2025-08-05 2025-06-30 13F ARDELYX PUT Put 29,100 -53.88 0 n/a n/a n/a
2025-05-12 2025-03-31 13F ARDELYX PUT Put 63,100 -51.05 0 n/a n/a n/a
2025-02-11 2024-12-31 13F ARDELYX PUT Put 128,900 -39.05 1 -100.00 n/a n/a n/a
2024-11-08 2024-09-30 13F ARDELYX PUT Put 211,500 -21.08 1 0.00 n/a n/a n/a
2024-07-25 2024-06-30 13F ARDELYX PUT Put 268,000 -3.14 2 -50.00 n/a n/a n/a
2024-04-25 2024-03-31 13F ARDELYX PUT Put 276,700 0.84 2 100.00 n/a n/a n/a
2024-02-02 2023-12-31 13F ARDELYX PUT Put 274,400 -7.92 2 0.00 n/a n/a n/a
2023-11-01 2023-09-30 13F ARDELYX PUT Put 298,000 59.19 1 n/a n/a n/a
2023-08-04 2023-06-30 13F ARDELYX PUT Put 187,200 157.14 1 n/a n/a n/a
2023-04-27 2023-03-31 13F ARDELYX PUT Put 72,800 -72.82 0 n/a n/a n/a
2023-02-02 2022-12-31 13F ARDELYX PUT Put 267,800 107.60 1 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ARDELYX PUT Put 129,000 56.74 153 218.75 n/a n/a n/a
2022-08-03 2022-06-30 13F ARDELYX PUT Put 82,300 24.70 48 -31.43 n/a n/a n/a
2022-05-02 2022-03-31 13F ARDELYX PUT Put 66,000 -21.71 70 -23.91 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ARDELYX PUT Put 84,300 -21.29 92 -89.19 n/a n/a n/a
2022-02-04 2021-12-31 13F ARDELYX PUT Put 107,100 851 n/a n/a n/a
2021-10-28 2021-09-30 13F ARDELYX PUT Put 107,100 10.30 851 15.63 n/a n/a n/a
2021-08-12 2021-06-30 13F ARDELYX PUT Put 97,100 220,581.82 736 2,437.93 n/a n/a n/a
2021-04-26 2021-03-31 13F ARDELYX PUT Put 44 -46.99 29 -45.28 n/a n/a n/a
2021-02-02 2020-12-31 13F ARDELYX PUT Put 83 88.64 53 82.76 n/a n/a n/a
2020-10-14 2020-09-30 13F ARDELYX PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-07-13 2020-06-30 13F ARDELYX PUT Put 129 -57.14 89 -47.95 n/a n/a n/a
2020-04-29 2020-03-31 13F ARDELYX PUT Put 301 -11.99 171 -33.20 n/a n/a n/a
2020-02-05 2019-12-31 13F ARDELYX PUT Put 342 155.22 256 312.90 n/a n/a n/a
2019-10-15 2019-09-30 13F ARDELYX PUT Put 134 -60.82 62 -75.78 n/a n/a n/a
2019-04-18 2019-03-31 13F ARDELYX PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-01-16 2018-12-31 13F ARDELYX PUT Put 21 3 n/a n/a n/a
2018-04-26 2018-03-31 13F ARDELYX PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F ARDELYX PUT Put 23 -8.00 5 -16.67 n/a n/a n/a
2017-10-25 2017-09-30 13F ARDELYX PUT Put 25 25.00 6 -40.00 n/a n/a n/a
2017-07-12 2017-06-30 13F ARDELYX PUT Put 20 10 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.