BSTZ vs WDC: Correlation
Measured on weekly returns over the past three years, BlackRock Science and Technology Term Trust (BSTZ) and Western Digital (WDC) carry a correlation of 0.58, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BSTZ and WDC?
On 3 years of weekly data the BSTZ/WDC correlation comes out at 0.58, moderate. Little has changed lately, as the 1-year reading of 0.52 lands near the 3-year figure. The 5-year figure is 0.53, and annualized covariance runs at 801.5 %².
By 3-year correlation, WDC places #11 of the 21 assets tracked against BSTZ. Their recent paths diverged sharply: over the last 12 months WDC outperformed by 416.9 percentage points (+57.4% for BSTZ against +474.3% for WDC). Risk is not evenly split, since WDC carries 2.4 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 WDC: side by side
| BSTZ (BlackRock Science and Technology Term Trust) | WDC (Western Digital) | |
|---|---|---|
| 1-year return | +57.4% | +474.3% |
| 5-year return | +31.6% | +889.2% |
| Volatility (ann.) | 23.7% | 58.0% |
| Beta vs S&P 500 | 1.19 | 2.15 |
| Max drawdown (3Y) | -25.3% | -49.6% |
| Market cap | $2.1B | $166.6B |
| P/E (trailing) | 6.7 | 17.4 |
| Dividend yield | 0.00% | 0.11% |
| Sector / category | US Listed | Information Technology |
Year-by-year returns
| Year | BSTZ | WDC |
|---|---|---|
| 2022 | -55.3% | -51.6% |
| 2023 | +18.7% | +66.0% |
| 2024 | +37.5% | +13.9% |
| 2025 | +25.1% | +283.7% |
| 2026 | +44.7% | +168.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BSTZ and WDC good diversifiers for each other?
Somewhat, no more. With 0.58 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between BSTZ and WDC?
Using weekly returns as of 2026-08-27: 0.58 over 3 years, with 0.52 over the last year and 0.53 over 5 years.
Is WDC a good diversifier for BSTZ?
Somewhat, no more. With 0.58 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.58 mean?
A reading of 0.58 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-wdc.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/bstz-vs-wdc/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: BSTZ correlations · WDC correlations
