Inspire Medical Systems, Inc. (INSP) Ownership
INSP ownership summary
as of October 17, 2026- Institutions
- 129.3% of shares outstanding
- Insiders
- 1.18% of shares outstanding
- Shares outstanding
- 28.9M
- Float
- 23.3M shares available to trade
- Short interest
- 19.00% 4.2M shares short
- Days to cover
- 5.01 short interest up 14.7% vs prior month
- Institutions 129.28%
- Insiders 1.18%
INSP top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 16.39% | 4.7M | $325.9M | +1.2M (+33.5%) | June 30, 2026 |
| 2 | Wellington Management Company LLP | 8.24% | 2.4M | $163.9M | −153,294 (−6.0%) | June 30, 2026 |
| 3 | Vanguard Portfolio Management, LLC | 7.23% | 2.1M | $143.7M | +451,788 (+27.6%) | June 30, 2026 |
| 4 | Soleus Capital Management, L.P. | 6.68% | 1.9M | $132.9M | +1.4M (+235.1%) | June 30, 2026 |
| 5 | AQR Capital Management LLC | 6.42% | 1.9M | $127.7M | +1.5M (+501.6%) | June 30, 2026 |
| 6 | Assenagon Asset Management SA | 5.98% | 1.7M | $118.9M | +1.2M (+232.3%) | June 30, 2026 |
| 7 | UBS Group AG | 5.69% | 1.6M | $113.2M | +1.0M (+157.5%) | June 30, 2026 |
| 8 | D. E. Shaw & Co LP | 5.09% | 1.5M | $101.2M | +281,925 (+23.7%) | June 30, 2026 |
| 9 | Nomura Holdings Inc | 4.74% | 1.4M | $94.2M | +1.4M (0.0%) | June 30, 2026 |
| 10 | Deerfield Management Co | 4.49% | 1.3M | $89.2M | −1.4M (−52.0%) | June 30, 2026 |
| 11 | Vanguard Capital Management, LLC | 4.40% | 1.3M | $87.4M | +4,190 (+0.3%) | June 30, 2026 |
| 12 | State Street Corp | 4.17% | 1.2M | $83.0M | +250,483 (+26.2%) | June 30, 2026 |
| 13 | Morgan Stanley - Brokerage Accounts | 2.74% | 791K | $54.4M | −659,412 (−45.5%) | June 30, 2026 |
| 14 | Artisan Partners Limited Partnership | 2.53% | 732K | $50.4M | −48,252 (−6.2%) | June 30, 2026 |
| 15 | Geode Capital Management, LLC | 2.42% | 701K | $48.2M | +190,602 (+37.4%) | June 30, 2026 |
| 16 | BRAIDWELL LP | 2.34% | 678K | $46.6M | — | June 30, 2026 |
| 17 | The Goldman Sachs Group Inc | 2.23% | 646K | $44.4M | −18,145 (−2.7%) | June 30, 2026 |
| 18 | UBS Asset Mgmt Americas Inc | 1.89% | 546K | $37.6M | +97,233 (+21.7%) | June 30, 2026 |
| 19 | Nantahala Capital Management, LLC | 1.86% | 539K | $37.1M | +538,948 (0.0%) | June 30, 2026 |
| 20 | Citadel Advisors Llc | 1.75% | 506K | $34.8M | +112,258 (+28.5%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 14 holders added 9.6M shares and 5 cut 2.3M.
INSP top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard Health Care Inv | 7.24% | 2.1M | $144.0M | — | June 30, 2026 |
| 2 | iShares Core S&P Small-Cap ETF | 5.95% | 1.7M | $118.4M | +417 (+0.0%) | September 30, 2026 |
| 3 | Vanguard MStar Total Stk Mkt Idx Invest | 3.16% | 914K | $62.9M | — | August 31, 2026 |
| 4 | iShares Russell 2000 ETF | 2.59% | 750K | $51.6M | −8,640 (−1.1%) | September 30, 2026 |
| 5 | Vanguard Small Cap Index | 2.29% | 662K | $45.6M | −1,242 (−0.2%) | August 31, 2026 |
| 6 | Xtrackers S&P 500 Swap ETF 1C | 1.75% | 505K | $34.8M | −3,728 (−0.7%) | December 31, 2025 |
| 7 | Artisan International Small-Mid Investor | 1.58% | 456K | $31.4M | −26,755 (−5.5%) | June 30, 2026 |
| 8 | Vanguard MStar Small Cap Growth Indx Inv | 1.31% | 380K | $26.1M | −3,348 (−0.9%) | August 31, 2026 |
| 9 | Fidelity Small Cap Index | 1.10% | 317K | $21.8M | +2,451 (+0.8%) | July 31, 2026 |
| 10 | iShares S&P Small-Cap 600 Growth ETF | 0.93% | 268K | $18.4M | — | September 30, 2026 |
| 11 | State Street SPDR Port S&P 600 Sm CpETF | 0.92% | 265K | $18.2M | — | September 30, 2026 |
| 12 | Federated Hermes MDT Mid Cap Growth A | 0.82% | 237K | $16.3M | +236,764 (0.0%) | June 30, 2026 |
| 13 | iShares Russell 2000 Growth ETF | 0.81% | 235K | $16.2M | −298 (−0.1%) | September 30, 2026 |
| 14 | Vanguard Strategic Equity Inv | 0.80% | 231K | $15.9M | +146,341 (+173.7%) | June 30, 2026 |
| 15 | UBS Lux Rbtc and Atmtn Eq seeding P acc | 0.78% | 224K | $15.4M | −747 (−0.3%) | June 30, 2026 |
| 16 | Vanguard Explorer Inv | 0.63% | 182K | $12.5M | +55,116 (+43.4%) | June 30, 2026 |
| 17 | Principal US Small Cap ETF | 0.63% | 182K | $12.5M | +90 (+0.0%) | September 30, 2026 |
| 18 | Vanguard Russell 2000 ETF | 0.58% | 167K | $11.5M | +3,984 (+2.4%) | August 31, 2026 |
| 19 | State Street® SPDR® S&P 600™ Sm Cp GrETF | 0.58% | 166K | $11.5M | — | September 30, 2026 |
| 20 | Schwab US Small-Cap ETF™ | 0.53% | 152K | $10.5M | +99 (+0.1%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
INSP insider transactions
latest 6| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-01-09 | John Rondoni | Sell | $100.00 | 109 | $10,900 |
| 2025-11-28 | Shawn Mccormick | Sell | $127.48 | 2,000 | $254,960 |
| 2025-08-29 | Richard Buchholz | Sell | $93.39 | 11,000 | $1.0M |
| 2025-08-08 | Myriam Curet | Sell | $77.28 | 4 | $309 |
| 2025-05-08 | Myriam Curet | Sell | $153.22 | 2 | $306 |
| 2025-05-02 | Shawn Mccormick | Sell | $160.00 | 360 | $57,600 |
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.
INSP shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns INSP
Institutional investors own 129.3% of Inspire Medical Systems's shares and insiders 1.18%. The largest holder is BlackRock Inc with 16.39% of the shares (4.7M), as of June 30, 2026. Among the top 20 institutions, 14 added shares and 5 reduced their stake in the latest filings. Short interest is 19.00% of the float, or 5.01 days of average trading volume. The share count rose 2,821.8% since 2016.
Related: INSP analyst forecast, INSP key metrics. See the INSP stock overview for the latest quote and news.
INSP ownership FAQ
Who owns the most Inspire Medical Systems stock?
The largest shareholders of Inspire Medical Systems are BlackRock Inc (16.39%), Wellington Management Company LLP (8.24%), Vanguard Portfolio Management, LLC (7.23%), Soleus Capital Management, L.P. (6.68%), AQR Capital Management LLC (6.42%).
What percentage of Inspire Medical Systems is owned by institutions?
Institutions hold 129.3% of Inspire Medical Systems's shares outstanding; insiders hold 1.18%.
Which funds own Inspire Medical Systems?
The largest fund holders of Inspire Medical Systems are Vanguard Health Care Inv (7.24%), iShares Core S&P Small-Cap ETF (5.95%), Vanguard MStar Total Stk Mkt Idx Invest (3.16%), iShares Russell 2000 ETF (2.59%), Vanguard Small Cap Index (2.29%).
What is Inspire Medical Systems's short interest?
4.2M shares of Inspire Medical Systems were sold short, 19.00% of the float; at the average daily volume it would take 5.01 days to cover.
Are insiders buying or selling Inspire Medical Systems?
Of the latest 6 reported insider transactions in Inspire Medical Systems (since May 2, 2025), 0 were purchases and 6 were sales.
How many shares of Inspire Medical Systems are outstanding?
Inspire Medical Systems has 28.9M shares outstanding, of which 23.3M are in the public float.