MGK vs SPY: Holdings Overlap
MGKVanguard Mega Cap Growth Index Fund
Vanguard · 59 holdings · $33.7B · as of 2026-03-31
SPYState Street® SPDR® S&P 500® ETF Trust
State Street (SPDR) · 504 holdings · $812.0B · as of 2026-08-06
Holdings snapshots are 128 days apart (MGK: 2026-03-31, SPY: 2026-08-06). Weights and index membership change between snapshots, so the true current overlap is typically higher than shown. For funds tracking the same index, the gap can be 5–15 points.
How similar are MGK and SPY?
Vanguard Mega Cap Growth Index Fund (MGK, by Vanguard) holds 59 positions; State Street® SPDR® S&P 500® ETF Trust (SPY, by State Street (SPDR)) holds 504. They have 58 holdings in common, and by portfolio weight the two funds are 50.6% identical. In practical terms the pair is moderately overlapping; they share a meaningful core, but each fund adds distinct exposure.
- Overlap by Weight
- 50.6%Sum of the smaller weight of each shared holding
- Shared Holdings
- 58MGK holds 59 · SPY holds 504
- Weight in Shared Holdings
- MGK 100%·SPY 51%Share of each fund's weight in stocks both funds own
Based on each fund's latest official holdings. How is this calculated?
What makes each fund different
Only in MGK
1 of 59 positions (0.3% of the fund) are not held by SPY.
SNOWSnowflake, Inc., Class A0.28%
Sector Breakdown
| Sector | MGK | SPY |
|---|---|---|
| Information Technology | 54.4% | 37.6% |
| Communication Services | 16.7% | 9.7% |
| Consumer Discretionary | 13.1% | 9.3% |
| Financials | 4.9% | 12.3% |
| Health Care | 5.2% | 8.9% |
| Other Sectors | 5.6% | 22.1% |
Share of each fund's portfolio weight by GICS-style sector, compiled from issuer fund data and our own classification of the holdings, not the issuers' published sector charts.
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| MGK | +3.8% | +10.2% | +19.4% | +24.7% | +14.0% | +18.8% | 0.32% |
| SPY | +3.4% | +14.0% | +23.7% | +21.2% | +13.3% | +15.3% | 0.97% |
Total returns including dividends, from adjusted daily closes as of 2026-08-07. 3Y/5Y/10Y are annualized. Yield is trailing-12-month distributions over the last close. Past performance does not predict future results.
Project the growth of $10,000 in MGK vs SPY →
Shared Holdings(58)
The top 10 shared positions account for 75% of the overlap, led by NVDA, AAPL and MSFT.
 NVDANVIDIA Corp. COM | 13.75% | 8.00% | 8.00% |
|---|---|---|---|
 AAPLApple Inc. COM | 12.60% | 6.92% | 6.92% |
 MSFTMicrosoft Corp. COM | 9.01% | 5.60% | 5.60% |
 AMZNAmazon.com, Inc. COM | 4.59% | 4.02% | 4.02% |
 GOOGLAlphabet Inc. CAP STK CL A | 5.51% | 3.16% | 3.16% |
 AVGOBroadcom Inc COM | 4.40% | 3.00% | 3.00% |
 GOOGAlphabet Inc. CAP STK CL C | 4.37% | 2.54% | 2.54% |
 METAMeta Platforms, Inc., Class A | 4.17% | 1.95% | 1.95% |
 LLYEli Lilly & Co. COM | 3.17% | 1.42% | 1.42% |
 TSLATesla Inc COM | 4.18% | 1.36% | 1.36% |
 AMDAdvanced Micro Devices Inc. COM | 1.49% | 1.20% | 1.20% |
 VVisa, Inc., Class A | 1.97% | 0.93% | 0.93% |
 MAMasterCard Incorporated CL A | 1.72% | 0.70% | 0.70% |
 LRCXLam Research Corporation COM NEW | 1.25% | 0.58% | 0.58% |
 PLTRPalantir Technologies, Inc., Class A | 1.42% | 0.54% | 0.54% |
 NFLXNetflix, Inc. COM | 1.76% | 0.47% | 0.47% |
 PANWPalo Alto Networks Inc COM | 0.71% | 0.44% | 0.44% |
 GEVGE Vernova Inc. COM | 1.14% | 0.41% | 0.41% |
 KLACKLA Corp. COM NEW | 0.98% | 0.38% | 0.38% |
 ORCLOracle Corp. COM | 1.18% | 0.37% | 0.37% |
 CRWDCrowdstrike Holdings, Inc., Class A | 0.56% | 0.32% | 0.32% |
 APHAmphenol Corporation CL A | 0.80% | 0.32% | 0.32% |
 ANETArista Networks Inc COM SHS | 0.70% | 0.30% | 0.30% |
 MCDMcDonald's Corp. COM | 0.63% | 0.30% | 0.30% |
 SNDKSandisk Corporation COM | 0.62% | 0.28% | 0.28% |
Frequently Asked Questions
How much do MGK and SPY overlap?
MGK and SPY overlap by 50.6% of portfolio weight. They share 58 holdings (MGK holds 59 positions and SPY holds 504), based on each fund's latest SEC-reported holdings.
Is it redundant to own both MGK and SPY?
The two portfolios are 50.6% identical by weight. Owning both is defensible: they share a meaningful core, but each fund adds exposure the other lacks.
What are the biggest shared holdings of MGK and SPY?
The largest positions held by both funds are NVDA, AAPL, MSFT, AMZN and GOOGL. Together the top 10 shared positions account for 75% of the total overlap.
What does MGK own that SPY doesn't?
1 positions (0.3% of MGK) are unique to MGK, led by SNOW. In the other direction, 446 positions (49.3% of SPY) are unique to SPY.