MDY vs SYM: Correlation
SPDR S&P MidCap 400 ETF (MDY) and Symbotic Inc. (SYM) show a moderate relationship: their 3-year correlation of weekly returns is 0.47.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and SYM?
Across a 3-year window, the weekly returns of MDY and SYM correlate at 0.47, moderate. Lately the two have drifted apart, with the 1-year correlation at 0.34 versus 0.47 over 3 years. Stretching to 5 years gives 0.23, with an annualized covariance of 668.7 %².
Among the 359 assets we track against MDY, SYM ranks #324 by 3-year correlation. The last year tells two different stories: MDY led by 32.1 percentage points, +18.3% for MDY against -13.8% for SYM. Note the risk asymmetry: SYM runs 5.2 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.
MDY vs SYM: side by side
| MDY (SPDR S&P MidCap 400 ETF) | SYM (Symbotic Inc.) | |
|---|---|---|
| 1-year return | +18.3% | -13.8% |
| 5-year return | +47.5% | +324.6% |
| Volatility (ann.) | 16.5% | 86.6% |
| Beta vs S&P 500 | 0.91 | 2.49 |
| Max drawdown (3Y) | -24.0% | -69.9% |
| Market cap | – | $24.9B |
| P/E (trailing) | – | 1028.5 |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
On the fund side, MDY sits in the Mid-Cap Blend category at State Street Investment Management, with $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | SYM |
|---|---|---|
| 2022 | -13.3% | +19.4% |
| 2023 | +16.1% | +329.9% |
| 2024 | +13.6% | -53.8% |
| 2025 | +7.2% | +150.9% |
| 2026 | +16.4% | -30.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and SYM good diversifiers for each other?
Reasonably. At 0.47, MDY and SYM keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between MDY and SYM?
The MDY/SYM correlation stands at 0.47 on a 3-year window (1 year: 0.34, 5 years: 0.23), computed from weekly returns as of 2026-08-27.
Is SYM a good diversifier for MDY?
Reasonably. At 0.47, MDY and SYM keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.47 mean?
On the −1 to +1 scale, 0.47 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-sym.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-sym/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: MDY correlations · SYM correlations
