MDY vs RVT: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and Royce Small-Cap Trust, Inc. (RVT) trade together? Their weekly returns over three years give a correlation of 0.92, which is very strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and RVT?
Over the past 3 years, MDY and RVT moved with a correlation of 0.92, which is very strong, meaning they move nearly in lockstep. Little has changed lately, as the 1-year reading of 0.87 lands near the 3-year figure. Over 5 years the correlation is 0.92, and the annualized covariance of weekly returns is 288.1 %².
Few assets follow MDY as closely as RVT, which ranks #3 of 359 tracked partners. The trailing year gives RVT the advantage: +18.3% versus +27.4%, a 9.1-point spread.
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.
MDY vs RVT: side by side
| MDY (SPDR S&P MidCap 400 ETF) | RVT (Royce Small-Cap Trust, Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +27.4% |
| 5-year return | +47.5% | +53.9% |
| Volatility (ann.) | 16.5% | 19.1% |
| Beta vs S&P 500 | 0.91 | 0.99 |
| Max drawdown (3Y) | -24.0% | -23.5% |
| Market cap | – | $2.3B |
| P/E (trailing) | – | 6.5 |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
MDY is a Mid-Cap Blend fund from State Street Investment Management: $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | RVT |
|---|---|---|
| 2022 | -13.3% | -26.3% |
| 2023 | +16.1% | +18.8% |
| 2024 | +13.6% | +17.9% |
| 2025 | +7.2% | +11.5% |
| 2026 | +16.4% | +21.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and RVT good diversifiers for each other?
Not really. At 0.92, the two trade almost as one position, and owning both buys little extra protection.
FAQ
What is the correlation between MDY and RVT?
As of 2026-08-27, the correlation of weekly returns between MDY and RVT is 0.92 over 3 years, 0.87 over 1 year and 0.92 over 5 years.
Is RVT a good diversifier for MDY?
Not really. At 0.92, the two trade almost as one position, and owning both buys little extra protection.
What does a correlation of 0.92 mean?
On the −1 to +1 scale, 0.92 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/mdy-vs-rvt.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-rvt/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · RVT correlations
