ABALX vs AGG: 9% overlap
American Funds American Balanced A and iShares Core U.S. Aggregate Bond ETF share 8.6% 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 4 months apart — ABALX as of 2026-03-31, 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.
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 AGG hold 349 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ABALX | in AGG | Δ |
|---|---|---|---|
| AGENCY-MBS | 2.7% | 24.1% | 21.3% |
| 68389X | 0.4% | 0.3% | 0.1% |
| 30303M | 0.2% | 0.2% | 0.0% |
| 46647P | 0.2% | 0.5% | 0.3% |
| 95000U | 0.2% | 0.3% | 0.1% |
| 06051G | 0.2% | 0.5% | 0.3% |
| 38141G | 0.2% | 0.3% | 0.2% |
| 023135 | 0.2% | 0.3% | 0.2% |
| 694308 | 0.3% | 0.1% | 0.1% |
| 161175 | 0.2% | 0.1% | 0.1% |
Where ABALX and AGG 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 | AGG | Δ |
|---|---|---|---|
| Treasuries | 12.3% | 46.5% | −34.2pp |
| Unclassified | 22.7% | 0.0% | +22.7pp |
| MBS Pass-Through | 2.7% | 24.1% | −21.3pp |
| Information Technology | 16.0% | 0.0% | +16.0pp |
| Corporate — industrial & other | 3.6% | 14.3% | −10.7pp |
| 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 AGG, 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
90.2% of ABALX by weight, held in no part of AGG.
59.2% of AGG 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 | AGG | |
|---|---|---|
| Top 10 holdings | 36.3% | 75.3% |
| Positions held | 1,439 | 1,864 |
| 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 AGG overlap?
ABALX and AGG overlap 8.6% by portfolio weight — largely distinct portfolios. They share 349 holdings. The figure comes from current issuer holdings files (ABALX as of 2026-03-31, AGG as of 2026-07-23).
How is the overlap between ABALX and AGG 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 AGG 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 AGG?
That depends on your goals — we state facts, not advice. At 8.6% overlap, each fund still contributes meaningfully distinct exposure.
What does ABALX own that AGG doesn't?
ABALX holds 1,439 positions and AGG holds 1,864; 1,089 of ABALX's positions don't appear in AGG at all, and they are 90.2% of ABALX by weight.
You probably hold more than two funds
This page compares ABALX and AGG. Paste your whole portfolio — brokerage, 401(k), IRA — and see the overlap across every fund at once, plus what you actually own underneath them and your own Effective Funds number. Free, no account, nothing stored.
X-ray my portfolio — free →Watch ABALX vs AGG
We re-read both funds’ published holdings every weeknight. Leave an address and we'll tell you when what's inside actually changes.
Not sending yet — email alerts are built but switched off, and you'll be among the first when they turn on. No spam, one-click unsubscribe.
Related comparisons
Sources: issuer holdings files, ABALX as of 2026-03-31, AGG as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.