MGK vs VBIAX: 1% overlap
Vanguard Mega Cap Growth ETF and Vanguard Balanced Index Admiral share 1.5% 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 3 months apart — VBIAX as of 2026-03-31, 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 2.0. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
MGK and VBIAX hold 4 of the same securities. The ten contributing most to the overlap figure:
| Holding | in MGK | in VBIAX | Δ |
|---|---|---|---|
| LLY | 3.4% | 0.7% | 2.6% |
| CASH | 0.5% | 1.8% | 1.3% |
| APH | 0.9% | 0.1% | 0.7% |
| WDC | 0.5% | 0.1% | 0.4% |
Where MGK and VBIAX 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 | VBIAX | Δ |
|---|---|---|---|
| Information Technology | 58.6% | 1.0% | +57.7pp |
| Unclassified | 0.0% | 55.1% | −55.1pp |
| Treasuries | 0.0% | 19.1% | −19.1pp |
| Communication Services | 16.2% | 0.5% | +15.7pp |
| Consumer Discretionary | 11.2% | 0.5% | +10.7pp |
| MBS Pass-Through | 0.0% | 8.1% | −8.1pp |
| Corporate — industrial & other | 0.0% | 5.8% | −5.8pp |
| Health Care | 4.9% | 1.2% | +3.7pp |
Δ is MGK minus VBIAX, 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
94.7% of MGK by weight, held in no part of VBIAX.
98.1% of VBIAX 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 | VBIAX | |
|---|---|---|
| Top 10 holdings | 63.5% | 45.2% |
| Positions held | 57 | 5,119 |
| Cost per $10,000 held, per year | $5 | $7 |
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 VBIAX overlap?
MGK and VBIAX overlap 1.5% by portfolio weight — largely distinct portfolios. They share 4 holdings. The figure comes from current issuer holdings files (MGK as of 2026-06-30, VBIAX as of 2026-03-31).
How is the overlap between MGK and VBIAX 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 VBIAX 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 VBIAX?
That depends on your goals — we state facts, not advice. At 1.5% overlap, each fund still contributes meaningfully distinct exposure.
What does MGK own that VBIAX doesn't?
MGK holds 57 positions and VBIAX holds 5,119; 53 of MGK's positions don't appear in VBIAX at all, and they are 94.7% of MGK by weight.
You probably hold more than two funds
This page compares MGK and VBIAX. 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 MGK vs VBIAX
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, MGK as of 2026-06-30, VBIAX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.