SPY vs VO: how much do they overlap?
SPDR S&P 500 ETF Trust (SPY) · Vanguard Mid-Cap ETF (VO)
overlap by weight · 252 shared holdings
SPY: 504 holdings (as of 09-Jul-2026) · VO: 289 holdings (as of 2026-03-31)
Note: the two funds' latest official filings have different dates, which can understate overlap slightly for funds tracking similar indexes.
Low overlap
What this means
SPY and VO hold mostly different stocks. Combining them genuinely spreads your exposure across different parts of the market.
Overlap by weight sums the smaller of the two funds' weights for every stock they both hold — it answers "how much of my money is in the same stocks either way?" See methodology.
Top shared holdings
| Company | Ticker | in SPY | in VO |
|---|---|---|---|
| Marvell Technology Inc | MRVL | 0.33% | 0.47% |
| Seagate Technology Holdings | STX | 0.31% | 0.93% |
| Western Digital Corp | WDC | 0.31% | 1% |
| Corning Inc | GLW | 0.23% | 0.57% |
| Vertiv Holdings Co A | VRT | 0.19% | 1.03% |
| Howmet Aerospace Inc | HWM | 0.17% | 1.01% |
| Fortinet Inc | FTNT | 0.16% | 0.26% |
| Newmont Corp | NEM | 0.16% | 0.64% |
| Quanta Services Inc | PWR | 0.15% | 0.89% |
| Cummins Inc | CMI | 0.14% | 0.81% |
FAQ
How much do SPY and VO overlap?
SPY and VO have a 16.2% overlap by weight, sharing 252 holdings (out of 504 in SPY and 289 in VO), based on official issuer holdings as of 09-Jul-2026.
What does 16.2% overlap mean?
SPY and VO hold mostly different stocks. Combining them genuinely spreads your exposure across different parts of the market.
Which stocks do SPY and VO both hold?
The largest shared positions are Marvell Technology Inc, Seagate Technology Holdings, Western Digital Corp, Corning Inc, Vertiv Holdings Co A. The full list of top shared holdings with weights in each fund is shown on this page.