ABALX vs FXNAX: 8% overlap
American Funds American Balanced A and Fidelity U.S. Bond Index share 8.3% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published 31 days apart — FXNAX as of 2026-02-28, the rest through 2026-03-31. 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 1.9. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
ABALX and FXNAX hold 266 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ABALX | in FXNAX | Δ |
|---|---|---|---|
| AGENCY-MBS | 2.7% | 16.5% | 13.7% |
| 68389X | 0.4% | 0.4% | 0.1% |
| 30303M | 0.2% | 0.2% | 0.0% |
| 46647P | 0.2% | 0.6% | 0.4% |
| 95000U | 0.2% | 0.3% | 0.1% |
| 06051G | 0.2% | 0.6% | 0.4% |
| 38141G | 0.2% | 0.4% | 0.2% |
| 023135 | 0.2% | 0.2% | 0.1% |
| 161175 | 0.2% | 0.2% | 0.0% |
| 694308 | 0.3% | 0.1% | 0.1% |
Where ABALX and FXNAX 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 | ABALX | FXNAX | Δ |
|---|---|---|---|
| Treasuries | 12.3% | 45.4% | −33.1pp |
| Information Technology | 16.0% | 0.0% | +16.0pp |
| MBS Pass-Through | 2.7% | 16.5% | −13.7pp |
| Unclassified | 22.7% | 9.5% | +13.2pp |
| Corporate — industrial & other | 3.6% | 14.1% | −10.6pp |
| Health Care | 6.7% | 0.0% | +6.7pp |
| Industrials | 6.0% | 0.0% | +6.0pp |
| Communication Services | 5.1% | 0.0% | +5.1pp |
Δ is ABALX minus FXNAX, 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
91.1% of ABALX by weight, held in no part of FXNAX.
66.4% of FXNAX by weight, held in no part of ABALX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| ABALX | FXNAX | |
|---|---|---|
| Top 10 holdings | 36.3% | 69.4% |
| Positions held | 1,439 | 1,266 |
| Cost per $10,000 held, per year | $56 | $3 |
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 ABALX and FXNAX overlap?
ABALX and FXNAX overlap 8.3% by portfolio weight — largely distinct portfolios. They share 266 holdings. The figure comes from current issuer holdings files (ABALX as of 2026-03-31, FXNAX as of 2026-02-28).
How is the overlap between ABALX and FXNAX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If ABALX holds a stock at 6% and FXNAX 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 ABALX and FXNAX?
That depends on your goals — we state facts, not advice. At 8.3% overlap, each fund still contributes meaningfully distinct exposure.
What does ABALX own that FXNAX doesn't?
ABALX holds 1,439 positions and FXNAX holds 1,266; 1,172 of ABALX's positions don't appear in FXNAX at all, and they are 91.1% of ABALX by weight.
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Related comparisons
Sources: issuer holdings files, ABALX as of 2026-03-31, FXNAX as of 2026-02-28. Weights are fractions of each fund. Diagnostics, not advice.