MGK vs RGAGX: 45% overlap
Vanguard Mega Cap Growth ETF and American Funds Growth Fund of America R6 share 45.3% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 4 months apart — RGAGX as of 2026-02-28, the rest through 2026-06-30. Each fund is compared using its most recent file, so any trading in between shows up as a difference.
You would hold two tickers and get the diversification of 1.5. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
MGK and RGAGX hold 42 of the same securities. The ten contributing most to the overlap figure:
| Holding | in MGK | in RGAGX | Δ |
|---|---|---|---|
| NVDA | 13.2% | 6.1% | 7.2% |
| AVGO | 4.3% | 4.3% | 0.0% |
| META | 4.1% | 4.2% | 0.2% |
| MSFT | 7.5% | 4.0% | 3.4% |
| LLY | 3.4% | 3.3% | 0.1% |
| GOOG | 4.6% | 2.9% | 1.7% |
| GOOGL | 5.9% | 2.9% | 3.0% |
| AMZN | 4.4% | 2.9% | 1.6% |
| TSLA | 3.9% | 2.6% | 1.3% |
| AAPL | 12.1% | 1.8% | 10.3% |
Where MGK and RGAGX differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | MGK | RGAGX | Δ |
|---|---|---|---|
| Information Technology | 58.6% | 30.6% | +28.1pp |
| Unclassified | 0.0% | 7.6% | −7.6pp |
| Industrials | 2.6% | 9.8% | −7.2pp |
| Health Care | 4.9% | 11.0% | −6.1pp |
| Communication Services | 16.2% | 13.2% | +3.0pp |
| Financials | 4.0% | 6.5% | −2.6pp |
| Consumer Staples | 0.4% | 2.4% | −2.0pp |
| Energy | 0.0% | 1.9% | −1.9pp |
Δ is MGK minus RGAGX, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
8.0% of MGK by weight, held in no part of RGAGX.
50.4% of RGAGX by weight, held in no part of MGK.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| MGK | RGAGX | |
|---|---|---|
| Top 10 holdings | 63.5% | 36.7% |
| Positions held | 57 | 309 |
| Cost per $10,000 held, per year | $5 | $30 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do MGK and RGAGX overlap?
MGK and RGAGX overlap 45.3% by portfolio weight — moderate overlap. They share 42 holdings. The figure comes from current issuer holdings files (MGK as of 2026-06-30, RGAGX as of 2026-02-28).
How is the overlap between MGK and RGAGX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If MGK holds a stock at 6% and RGAGX holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both MGK and RGAGX?
That depends on your goals — we state facts, not advice. At 45.3% overlap, each fund still contributes meaningfully distinct exposure.
What does MGK own that RGAGX doesn't?
MGK holds 57 positions and RGAGX holds 309; 15 of MGK's positions don't appear in RGAGX at all, and they are 8.0% of MGK by weight.
You probably hold more than two funds
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Related comparisons
Sources: issuer holdings files, MGK as of 2026-06-30, RGAGX as of 2026-02-28. Weights are fractions of each fund. Diagnostics, not advice.