Ardelyx, Inc. (ARDX) Ownership
ARDX ownership summary
as of October 18, 2026- Institutions
- 73.2% of shares outstanding
- Insiders
- 3.04% of shares outstanding
- Shares outstanding
- 258.2M
- Float
- 210.7M shares available to trade
- Short interest
- 10.95% 27.7M shares short
- Days to cover
- 6.68 short interest up 8.1% vs prior month
- Institutions 73.17%
- Insiders 3.04%
- Other investors 23.79%
ARDX top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 9.10% | 23.5M | $72.6M | +2.3M (+11.1%) | June 30, 2026 |
| 2 | Rubric Capital Management LP | 6.28% | 16.2M | $50.1M | +14.3M (+770.7%) | June 30, 2026 |
| 3 | Millennium Management LLC | 5.38% | 13.9M | $43.0M | −3.9M (−22.1%) | June 30, 2026 |
| 4 | State Street Corp | 5.17% | 13.4M | $41.3M | −248,179 (−1.8%) | June 30, 2026 |
| 5 | Vanguard Capital Management, LLC | 4.06% | 10.5M | $32.4M | +105,982 (+1.0%) | June 30, 2026 |
| 6 | Delaware Management Holdings Inc | 3.70% | 9.5M | $29.5M | +1.4M (+16.9%) | June 30, 2026 |
| 7 | HHG PLC | 3.24% | 8.4M | $25.9M | −6.1M (−42.3%) | March 31, 2026 |
| 8 | Vanguard Portfolio Management, LLC | 3.11% | 8.0M | $24.8M | +1.4M (+20.5%) | June 30, 2026 |
| 9 | Geode Capital Management, LLC | 2.48% | 6.4M | $19.8M | +394,281 (+6.6%) | June 30, 2026 |
| 10 | Jupiter Topco LLC | 2.05% | 5.3M | $16.4M | +5.3M (0.0%) | June 30, 2026 |
| 11 | Two Sigma Investments LLC | 2.02% | 5.2M | $16.1M | +935,780 (+21.9%) | June 30, 2026 |
| 12 | Nuveen, LLC | 1.55% | 4.0M | $12.4M | −1.2M (−23.6%) | June 30, 2026 |
| 13 | The Goldman Sachs Group Inc | 1.43% | 3.7M | $11.4M | +468,824 (+14.6%) | June 30, 2026 |
| 14 | AIGH Capital Management, LLC | 1.24% | 3.2M | $9.9M | +3.2M (0.0%) | June 30, 2026 |
| 15 | Morgan Stanley - Brokerage Accounts | 0.93% | 2.4M | $7.4M | +680,573 (+39.8%) | June 30, 2026 |
| 16 | AQR Capital Management LLC | 0.90% | 2.3M | $7.2M | −123,230 (−5.1%) | June 30, 2026 |
| 17 | Northern Trust Corp | 0.88% | 2.3M | $7.0M | +209,096 (+10.1%) | June 30, 2026 |
| 18 | Rock Springs Capital Management LP | 0.87% | 2.2M | $6.9M | −57,704 (−2.5%) | June 30, 2026 |
| 19 | Charles Schwab Investment Management Inc | 0.86% | 2.2M | $6.8M | +97,662 (+4.6%) | June 30, 2026 |
| 20 | Bank of America Corp | 0.84% | 2.2M | $6.7M | −173,494 (−7.4%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 13 holders added 30.8M shares and 7 cut 11.9M.
ARDX top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Nomura Small Cap Core I | 2.96% | 7.6M | $23.6M | — | August 31, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 2.87% | 7.4M | $22.9M | — | August 31, 2026 |
| 3 | State Street® SPDR® S&P® Biotech ETF | 2.84% | 7.3M | $22.6M | −139,900 (−1.9%) | September 30, 2026 |
| 4 | iShares Russell 2000 ETF | 2.44% | 6.3M | $19.5M | −72,576 (−1.1%) | September 30, 2026 |
| 5 | Invesco Biotechnology & Genome ETF | 1.20% | 3.1M | $9.6M | — | September 30, 2026 |
| 6 | Vanguard Strategic Equity Inv | 1.04% | 2.7M | $8.3M | +680,655 (+33.8%) | June 30, 2026 |
| 7 | Fidelity Small Cap Index | 1.03% | 2.7M | $8.3M | +21,576 (+0.8%) | July 31, 2026 |
| 8 | iShares Russell 2000 Growth ETF | 0.88% | 2.3M | $7.0M | −2,878 (−0.1%) | September 30, 2026 |
| 9 | Janus Global Life Science AUSD | 0.80% | 2.1M | $6.3M | −386,778 (−15.8%) | June 30, 2026 |
| 10 | BlackRock Advantage Small Cap Core Instl | 0.67% | 1.7M | $5.3M | +363,118 (+26.8%) | August 31, 2026 |
| 11 | Vanguard Explorer Inv | 0.58% | 1.5M | $4.7M | +249,875 (+19.9%) | June 30, 2026 |
| 12 | Vanguard Russell 2000 ETF | 0.54% | 1.4M | $4.3M | +33,503 (+2.4%) | August 31, 2026 |
| 13 | Schwab US Small-Cap ETF™ | 0.52% | 1.3M | $4.1M | +900 (+0.1%) | September 30, 2026 |
| 14 | Fidelity Extended Market Index | 0.47% | 1.2M | $3.8M | −10,398 (−0.8%) | August 31, 2026 |
| 15 | Nuveen Quant Small Cap Equity R6 | 0.46% | 1.2M | $3.7M | — | August 31, 2026 |
| 16 | International Biotechnology Ord | 0.45% | 1.2M | $3.6M | — | June 30, 2026 |
| 17 | Nuveen Quant Small/Mid Cap Eq R6 | 0.36% | 921K | $2.8M | — | August 31, 2026 |
| 18 | Vanguard Strategic Small-Cap Equity Inv | 0.30% | 782K | $2.4M | +168,038 (+27.4%) | June 30, 2026 |
| 19 | First Trust Small Cap Gr AlphaDEX® ETF | 0.29% | 755K | $2.3M | +1,333 (+0.2%) | September 30, 2026 |
| 20 | CREF Total Global Stock Account R3 | 0.29% | 747K | $2.3M | — | July 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
ARDX insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-16 | Michael Raab | Sell | $5.84 | 41,666 | $243,329 |
| 2026-02-20 | David M Mott | Buy | $5.84 | 333,333 | $1.9M |
| 2026-02-20 | Susan Hohenleitner | Sell | $5.85 | 2,033 | $11,893 |
| 2026-02-20 | Mike Kelliher | Sell | $5.85 | 9,595 | $56,131 |
| 2026-02-20 | Michael Raab | Sell | $5.85 | 45,982 | $268,995 |
| 2026-02-20 | Laura A Williams | Sell | $5.85 | 8,176 | $47,830 |
| 2026-02-20 | Joseph James Reilly | Sell | $5.85 | 4,991 | $29,197 |
| 2026-02-20 | John E Bishop | Sell | $5.85 | 3,179 | $18,597 |
| 2026-02-20 | James Parker Brady | Sell | $5.85 | 2,543 | $14,877 |
| 2026-02-20 | Eric Duane Foster | Sell | $5.85 | 10,439 | $61,068 |
| 2026-01-08 | Laura A Williams | Sell | $6.98 | 50,000 | $349,000 |
| 2025-11-21 | Elizabeth A Grammer | Sell | $5.54 | 5,995 | $33,212 |
| 2025-11-21 | Laura A Williams | Sell | $5.54 | 6,426 | $35,600 |
| 2025-11-21 | Michael Raab | Sell | $5.54 | 46,887 | $259,754 |
| 2025-11-21 | Mike Kelliher | Sell | $5.54 | 5,560 | $30,802 |
| 2025-08-26 | Laura A Williams | Sell | $6.12 | 80,000 | $489,600 |
| 2025-08-21 | Elizabeth A Grammer | Sell | $5.93 | 5,841 | $34,637 |
| 2025-08-21 | Mike Kelliher | Sell | $5.93 | 5,417 | $32,123 |
| 2025-08-21 | Michael Raab | Sell | $5.93 | 45,687 | $270,924 |
| 2025-08-21 | Laura A Williams | Sell | $5.93 | 6,261 | $37,128 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
ARDX shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns ARDX
Institutional investors own 73.2% of Ardelyx's shares and insiders 3.04%. The largest holder is BlackRock Inc with 9.10% of the shares (23.5M), as of June 30, 2026. Among the top 20 institutions, 13 added shares and 7 reduced their stake in the latest filings. Short interest is 10.95% of the float, or 6.68 days of average trading volume. The share count rose 1,218.7% since 2014.
Related: ARDX analyst forecast, ARDX key metrics. See the ARDX stock overview for the latest quote and news.
ARDX ownership FAQ
Who owns the most Ardelyx stock?
The largest shareholders of Ardelyx are BlackRock Inc (9.10%), Rubric Capital Management LP (6.28%), Millennium Management LLC (5.38%), State Street Corp (5.17%), Vanguard Capital Management, LLC (4.06%).
What percentage of Ardelyx is owned by institutions?
Institutions hold 73.2% of Ardelyx's shares outstanding; insiders hold 3.04%.
Which funds own Ardelyx?
The largest fund holders of Ardelyx are Nomura Small Cap Core I (2.96%), Vanguard MStar Total Stk Mkt Idx Invest (2.87%), State Street® SPDR® S&P® Biotech ETF (2.84%), iShares Russell 2000 ETF (2.44%), Invesco Biotechnology & Genome ETF (1.20%).
What is Ardelyx's short interest?
27.7M shares of Ardelyx were sold short, 10.95% of the float; at the average daily volume it would take 6.68 days to cover.
Are insiders buying or selling Ardelyx?
Of the latest 20 reported insider transactions in Ardelyx (since August 21, 2025), 1 were purchases and 19 were sales.
How many shares of Ardelyx are outstanding?
Ardelyx has 258.2M shares outstanding, of which 210.7M are in the public float.