INSP vs SPY: Correlation
Measured on weekly returns over the past three years, Inspire Medical Systems, Inc. (INSP) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.17, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are INSP and SPY?
On 3 years of weekly data the INSP/SPY correlation comes out at 0.17, weak. The link has tightened recently: the 1-year correlation (0.29) runs above the 3-year figure (0.17). The 5-year figure is 0.30, and annualized covariance runs at 161.3 %².
Out of 10 assets tracked against INSP, SPY lands near the bottom at #6. The last year tells two different stories: SPY led by 54.7 percentage points, -34.1% for INSP against +20.6% for SPY. Risk is not evenly split, since INSP carries 4.6 times the volatility of the other side.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
INSP vs SPY: side by side
| INSP (Inspire Medical Systems, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -34.1% | +20.6% |
| 5-year return | -72.6% | +82.4% |
| Volatility (ann.) | 67.2% | 14.5% |
| Beta vs S&P 500 | 0.77 | 1.00 |
| Max drawdown (3Y) | -84.1% | -18.8% |
| Market cap | $1.8B | – |
| P/E (trailing) | 13.6 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | ETF · US Large Cap |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | INSP | SPY |
|---|---|---|
| 2022 | +9.5% | -18.2% |
| 2023 | -19.2% | +26.2% |
| 2024 | -8.9% | +24.9% |
| 2025 | -50.2% | +17.7% |
| 2026 | -34.1% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are INSP and SPY good diversifiers for each other?
Yes. With a correlation of 0.17, INSP and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between INSP and SPY?
Using weekly returns as of 2026-08-27: 0.17 over 3 years, with 0.29 over the last year and 0.30 over 5 years.
Is SPY a good diversifier for INSP?
Yes. With a correlation of 0.17, INSP and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of 0.17 mean?
On the −1 to +1 scale, 0.17 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/insp-vs-spy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/insp-vs-spy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: INSP correlations · SPY correlations
