BSTZ vs SPY: Correlation
Measured on weekly returns over the past three years, BlackRock Science and Technology Term Trust (BSTZ) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.72, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BSTZ and SPY?
Across a 3-year window, the weekly returns of BSTZ and SPY correlate at 0.72, strong. Recent behaviour matches the longer record: 0.66 over 1 year against 0.72 over 3. Stretching to 5 years gives 0.77, with an annualized covariance of 247.6 %².
Among the 21 assets we track against BSTZ, SPY ranks #7 by 3-year correlation. Correlation aside, the last 12 months split them widely, with BSTZ ahead by 36.8 points (+57.4% versus +20.6%). Risk is not evenly split, since BSTZ carries 1.6 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.
BSTZ vs SPY: side by side
| BSTZ (BlackRock Science and Technology Term Trust) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +57.4% | +20.6% |
| 5-year return | +31.6% | +82.4% |
| Volatility (ann.) | 23.7% | 14.5% |
| Beta vs S&P 500 | 1.19 | 1.00 |
| Max drawdown (3Y) | -25.3% | -18.8% |
| Market cap | $2.1B | – |
| P/E (trailing) | 6.7 | – |
| 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 | BSTZ | SPY |
|---|---|---|
| 2022 | -55.3% | -18.2% |
| 2023 | +18.7% | +26.2% |
| 2024 | +37.5% | +24.9% |
| 2025 | +25.1% | +17.7% |
| 2026 | +44.7% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BSTZ and SPY good diversifiers for each other?
Only partially. A correlation of 0.72 means BSTZ and SPY 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 BSTZ and SPY?
The BSTZ/SPY correlation stands at 0.72 on a 3-year window (1 year: 0.66, 5 years: 0.77), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for BSTZ?
Only partially. A correlation of 0.72 means BSTZ and SPY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.72 mean?
A reading of 0.72 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/bstz-vs-spy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/bstz-vs-spy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: BSTZ correlations · SPY correlations
