BST vs SPYG: Correlation
BlackRock Science and Technology Trust (BST) and SPDR Portfolio S&P 500 Growth ETF (SPYG) show a very strong relationship: their 3-year correlation of weekly returns is 0.86.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BST and SPYG?
Over the past 3 years, BST and SPYG moved with a correlation of 0.86, which is very strong, meaning they move nearly in lockstep. Recent behaviour matches the longer record: 0.81 over 1 year against 0.86 over 3. Over 5 years the correlation is 0.87, and the annualized covariance of weekly returns is 360.3 %².
In BST's tracked universe of 25 assets, SPYG sits right near the top at #3. Correlation aside, the last 12 months split them widely, with BST ahead by 18.3 points (+40.7% versus +22.4%).
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.
BST vs SPYG: side by side
| BST (BlackRock Science and Technology Trust) | SPYG (SPDR Portfolio S&P 500 Growth ETF) | |
|---|---|---|
| 1-year return | +40.7% | +22.4% |
| 5-year return | +46.7% | +85.9% |
| Volatility (ann.) | 22.2% | 18.9% |
| Beta vs S&P 500 | 1.27 | 1.25 |
| Max drawdown (3Y) | -23.4% | -22.1% |
| Market cap | – | – |
| P/E (trailing) | 6.9 | – |
| Dividend yield | 0.00% | 0.49% |
| Expense ratio | – | 0.04% |
| Assets under management | – | $52.2B |
| Sector / category | US Listed | ETF · US Style |
SPYG is a Large Growth fund from State Street Investment Management: $52.2B under management, 148 holdings, a 0.04% expense ratio, a 0.49% trailing dividend yield.
Year-by-year returns
| Year | BST | SPYG |
|---|---|---|
| 2022 | -38.3% | -29.4% |
| 2023 | +30.1% | +30.0% |
| 2024 | +18.0% | +36.0% |
| 2025 | +23.7% | +22.1% |
| 2026 | +30.9% | +14.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BST and SPYG good diversifiers for each other?
Not really. At 0.86, the two trade almost as one position, and owning both buys little extra protection.
FAQ
What is the correlation between BST and SPYG?
Using weekly returns as of 2026-08-27: 0.86 over 3 years, with 0.81 over the last year and 0.87 over 5 years.
Is SPYG a good diversifier for BST?
Not really. At 0.86, the two trade almost as one position, and owning both buys little extra protection.
What does a correlation of 0.86 mean?
A reading of 0.86 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/bst-vs-spyg.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/bst-vs-spyg/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: BST correlations · SPYG correlations
