ARCT vs IBB: Correlation
How closely do Arcturus Therapeutics Holdings Inc. (ARCT) and iShares Biotechnology ETF (IBB) trade together? Their weekly returns over three years give a correlation of 0.51, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ARCT and IBB?
Across a 3-year window, the weekly returns of ARCT and IBB correlate at 0.51, moderate. The relationship has been stable: the 1-year correlation (0.42) sits close to the 3-year figure. Stretching to 5 years gives 0.56, with an annualized covariance of 959.7 %².
Few assets follow ARCT as closely as IBB, which ranks #3 of 14 tracked partners. Correlation aside, the last 12 months split them widely, with IBB ahead by 61.9 points (-6.5% versus +55.4%). Note the risk asymmetry: ARCT runs 4.4 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
ARCT vs IBB: side by side
| ARCT (Arcturus Therapeutics Holdings Inc.) | IBB (iShares Biotechnology ETF) | |
|---|---|---|
| 1-year return | -6.5% | +55.4% |
| 5-year return | -69.9% | +26.6% |
| Volatility (ann.) | 90.6% | 20.7% |
| Beta vs S&P 500 | 2.39 | 0.81 |
| Max drawdown (3Y) | -87.5% | -24.9% |
| Market cap | $0.5B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.22% |
| Expense ratio | – | 0.44% |
| Assets under management | – | $9.2B |
| Sector / category | US Listed | ETF · Thematic |
IBB, iShares's Health fund, carries $9.2B under management, 235 holdings, a 0.44% expense ratio, a 0.22% trailing dividend yield.
Year-by-year returns
| Year | ARCT | IBB |
|---|---|---|
| 2022 | -54.2% | -13.7% |
| 2023 | +85.9% | +3.8% |
| 2024 | -46.2% | -2.4% |
| 2025 | -63.9% | +28.0% |
| 2026 | +163.8% | +27.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ARCT and IBB good diversifiers for each other?
Only partially. A correlation of 0.51 means ARCT and IBB share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between ARCT and IBB?
As of 2026-08-27, the correlation of weekly returns between ARCT and IBB is 0.51 over 3 years, 0.42 over 1 year and 0.56 over 5 years.
Is IBB a good diversifier for ARCT?
Only partially. A correlation of 0.51 means ARCT and IBB share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.51 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/arct-vs-ibb.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/arct-vs-ibb/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: ARCT correlations · IBB correlations
