DIA vs RGAGX: 19% overlap

SPDR Dow Jones Industrial Average ETF and American Funds Growth Fund of America R6 share 18.6% 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 5 months apart — RGAGX as of 2026-02-28, the rest through 2026-07-23. Each fund is compared using its most recent file, so any trading in between shows up as a difference.

Hold both, 50/50
1.8Effective Funds

You would hold two tickers and get the diversification of 1.8. Two funds that shared nothing would score 2.0; two identical funds score 1.0.

Overlap
18.6%
DIA expense ratio
0.16%
RGAGX expense ratio
0.30%

Top shared holdings

DIA and RGAGX hold 23 of the same securities. The ten contributing most to the overlap figure:

Holdingin DIAin RGAGXΔ
MSFT4.4%4.0%0.4%
GOOGL3.6%2.9%0.7%
AMZN2.7%2.9%0.2%
NVDA2.4%6.1%3.7%
AAPL3.7%1.8%1.9%
V4.0%0.8%3.2%
BA2.4%0.5%1.9%
AMGN4.3%0.5%3.8%
CAT10.3%0.5%9.8%
CRM1.8%0.4%1.4%

Where DIA 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.

SectorDIARGAGXΔ
Financials28.6%6.5%+22.1pp
Information Technology15.9%30.6%14.6pp
Communication Services4.7%13.2%8.5pp
Industrials17.5%9.8%+7.6pp
Unclassified0.0%7.6%7.6pp
Consumer Discretionary9.9%12.7%2.8pp
Health Care13.6%11.0%+2.6pp
Materials3.6%1.5%+2.0pp

Δ is DIA 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

Only in DIA
7 positions

15.5% of DIA by weight, held in no part of RGAGX.

Only in RGAGX
285 positions

76.5% of RGAGX by weight, held in no part of DIA.

A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.

Concentration and cost

DIARGAGX
Top 10 holdings56.2%36.7%
Positions held31309
Cost per $10,000 held, per year$16$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 DIA and RGAGX overlap?

DIA and RGAGX overlap 18.6% by portfolio weight — moderate overlap. They share 23 holdings. The figure comes from current issuer holdings files (DIA as of 2026-07-23, RGAGX as of 2026-02-28).

How is the overlap between DIA and RGAGX calculated?

As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If DIA 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 DIA and RGAGX?

That depends on your goals — we state facts, not advice. At 18.6% overlap, each fund still contributes meaningfully distinct exposure.

What does DIA own that RGAGX doesn't?

DIA holds 31 positions and RGAGX holds 309; 7 of DIA's positions don't appear in RGAGX at all, and they are 15.5% of DIA by weight.

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Related comparisons

Sources: issuer holdings files, DIA as of 2026-07-23, RGAGX as of 2026-02-28. Weights are fractions of each fund. Diagnostics, not advice.