Rock Springs Capital INSP Position
Active5-Fund ConvergenceRock Springs Capital increased their position in Inspire Medical Systems, Inc. (INSP) in Q4 2025, holding $12.1M worth of shares across 131,000 shares.
The position was first reported in Q3 2023 and has been tracked across 10 quarterly 13F filings.
INSP is a convergence signal: 5 specialist biotech funds hold this stock, suggesting high institutional conviction.
There is an upcoming Phase 3 readout in 318 days (Feb 28, 2027), making the timing of Rock Springs's position particularly relevant.
Short interest stands at 14.6% of float with 3.4 days to cover, indicating significant bearish positioning against Rock Springs's long thesis.
About Inspire Medical Systems, Inc.
Inspire Medical Systems, Inc., a medical technology company, focuses on the development and commercialization of minimally invasive solutions for patients with obstructive sleep apnea (OSA) in the United States and internationally. The company offers Inspire system, a neurostimulation technology that provides a safe and effective treatment for moderate to severe OSA. It also develops a novel, a closed-loop solution that continuously monitors a patient's breathing and delivers mild hypoglossal nerve stimulation to maintain an open airway. The company was incorporated in 2007 and is headquartered in Golden Valley, Minnesota.
Full company profile →Short Interest
14.6%
3.4 days to cover
Rock Springs Capital INSP Position History
| Quarter | Action | Shares | Change | Value |
|---|---|---|---|---|
| Q4 2025 | Increased | 131,000 | +20,500 | $12.1M |
| Q3 2025 | Increased | 110,500 | +3,000 | $8.2M |
| Q2 2025 | Increased | 107,500 | +8,250 | $13.9M |
| Q1 2025 | Decreased | 99,250 | -30,750 | $15.8M |
| Q4 2024 | Held | 130,000 | — | $24.1M |
| Q3 2024 | Held | 130,000 | — | $27.4M |
| Q2 2024 | Decreased | 130,000 | -500 | $17.4M |
| Q1 2024 | Increased | 130,500 | +31,500 | $28.0M |
| Q4 2023 | Increased | 99,000 | +54,500 | $20.1M |
| Q3 2023 | New | 44,500 | +44,500 | $8.8M |
Frequently Asked Questions
Does Rock Springs Capital own INSP?
Yes. As of Q4 2025, Rock Springs Capital holds 131,000 shares of Inspire Medical Systems, Inc. (INSP) valued at $12.1M. This data comes from their SEC 13F filing.
How many hedge funds own INSP?
5 specialist biotech hedge funds currently hold INSP, including Deerfield Management, Driehaus Capital, Eventide Asset Management and 1 more. When 3 or more specialist funds hold the same stock, BiotechEdge flags it as a convergence signal.
When did Rock Springs Capital first buy INSP?
Rock Springs Capital's position in INSP was first reported in Q3 2023. 13F filings are reported with a 45-day delay, so the actual purchase may have occurred earlier in the quarter.
Is Rock Springs Capital's INSP position increasing or decreasing?
Rock Springs Capital increased their INSP position in the most recent quarter, adding 20,500 shares.
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