MGK vs SPYG: Which ETF Is Better in 2026?
A metric-by-metric comparison of Vanguard Mega Cap Growth Index Fund (MGK) and State Street SPDR Portfolio S&P 500 Growth ETF (SPYG) — both US Large Cap Growth funds — using ETFValuer's daily-updated rankings.
Educational content — not financial advice. Data as of July 25, 2026. ~5 minute read.
The Verdict
MGK and SPYG are close to the same fund wearing different labels. Both sit in the US Large Cap Growth category and their daily returns move almost identically, so this is not really a question of which fund is better — it is a question of which one is cheaper to own and easier to trade in your account. Everything below is about finding the small, structural edges, because the investment exposure is a wash.
On ETFValuer's overall model — which blends return, risk-adjusted performance, cost, drawdown, size and volatility — SPYG scores higher: 67.7 (Grade B) versus 61.3 for MGK. That doesn't make MGK a bad fund; it means SPYG currently edges it out on this specific mix of factors. Read the metric-by-metric breakdown below before deciding which matters more for your own portfolio.
Head-to-Head: Every Metric
| MGK | SPYG | |
|---|---|---|
| Category | US Large Cap Growth | US Large Cap Growth |
| Expense ratio | 0.05% | 0.04% |
| Fund size (AUM) | $33.3B | $53.0B |
| Dividend yield | 0.33% | 0.40% |
| 1-year return | +13.05% | +18.08% |
| 3-year return | +76.92% | +86.66% |
| Volatility | 17.97% | 17.74% |
| Max drawdown | -23.36% | -22.14% |
| Sharpe ratio | 0.45 | 0.74 |
| ETFValuer score | 61.3 | 67.7 |
| Grade | C | B |
| Overall rank | #220 | #144 |
Bold marks the better value in each row. "Better" is directional only (e.g. lower cost, higher return) — it isn't a recommendation by itself. See the full methodology.
Cost
On cost, the two are essentially tied — MGK charges 0.05% a year versus SPYG's 0.04%. A difference this small (about $1.00 a year on a $10,000 position) isn't a reason to choose one fund over the other. That matters more than usual here: when two funds track the same exposure this closely, fee is normally the whole argument — and with the fees this close, there is no argument left. Liquidity and whichever one trades commission-free in your account become the tiebreaker.
What MGK's Fees Cost You
MGK charges an expense ratio of 0.05% a year, deducted automatically from the fund's value. Small percentages compound into real money — adjust the figures below to see the impact on your own numbers.
Assumes a constant gross return and no additional contributions — a simplification, but it isolates exactly what the expense ratio costs. Try the full fee calculator to model contributions and compare any two funds.
Performance & Risk
Over the trailing 3 years, SPYG returned +86.66% versus +76.92% for MGK — a gap of about 9.7 percentage points. On risk, SPYG has held up better historically, with a shallower max drawdown (-22.14% vs. -23.36%). SPYG currently has the better risk-adjusted return (Sharpe ratio of 0.74 vs. 0.45), meaning it delivered more return per unit of volatility taken on.
How Closely Do They Track Each Other?
Over the last 3.0 years of daily returns (752 shared trading days), MGK and SPYG show a extremely high correlation of 0.986 — very close substitutes. Holding both would add very little diversification: when one falls, the other almost always falls with it. Treat these as alternatives to each other, not as complements in the same portfolio.
| Measure | Value | What it means |
|---|---|---|
| Daily return correlation | 0.986 | Extremely high — very close substitutes |
| R-squared | 97.2% | 97.2% of MGK's daily moves are explained by SPYG's |
| Tracking error (annualised) | 3.44% | Typical yearly spread between the two funds' returns |
| Annualised return over 3.0y | MGK +21.52% · SPYG +23.49% | SPYG ahead by 1.97 points a year |
Correlation alone understates how far these can drift. Across every rolling 12-month window in the period, MGK finished as much as +2.8 points ahead of SPYG at the best extreme and -6.5 points at the worst — a 9.3-point spread between the best and worst year of relative performance. Two funds can correlate tightly day to day and still deliver very different outcomes over any single year you happen to hold them.
Calculated from daily total returns over the trailing 3-year window, recomputed every day this site refreshes. Correlation of 1.00 means the two funds moved in lockstep; 0.00 means their daily moves were unrelated.
Holdings Overlap
MGK and SPYG hold 8 of the same companies among their top 10 positions. Those shared names make up 61.6% of MGK and 56.5% of SPYG. That's heavy duplication — owning both largely doubles down on the same companies rather than spreading risk. Most investors should pick one.
| Shared Holding | MGK Weight | SPYG Weight |
|---|---|---|
| NVIDIA Corp | 13.75% | 14.62% |
| Alphabet Inc | 9.88% | 10.40% |
| Apple Inc | 12.60% | 6.43% |
| Microsoft Corp | 9.01% | 9.48% |
| Broadcom Inc | 4.40% | 5.06% |
| Meta Platforms Inc | 4.17% | 4.32% |
| Amazon.com Inc | 4.59% | 3.72% |
| Eli Lilly & Co | 3.17% | 2.51% |
Compares the top 10 reported holdings from each fund's most recent SEC N-PORT-P filing, so it understates total overlap — funds tracking similar indexes overlap far more deeply than the top 10 alone can show. Search any company across all tracked funds with the Stock Overlap tool.
Which One Should You Pick?
Lean MGK if…
- You prefer to keep holdings under one roof at Vanguard
Lean SPYG if…
- You want the lower running cost — 0.04% vs 0.05%, about $1 a year less on a $10,000 position
- Current income matters to you — it yields 0.40% against 0.33%
- You care about return per unit of risk — its Sharpe ratio of 0.74 beats 0.45
- You weight recent results heavily — it returned 86.7% over 3 years against 76.9%
Whichever you pick, holding both at full weight is usually the wrong answer — see the overlap and correlation sections above.
Frequently Asked Questions
Is MGK or SPYG better?
On ETFValuer's overall model — which blends return, risk-adjusted performance, cost, drawdown, size and volatility — SPYG scores higher: 67.7 (Grade B) versus 61.3 for MGK. That doesn't make MGK a bad fund; it means SPYG currently edges it out on this specific mix of factors. Read the metric-by-metric breakdown below before deciding which matters more for your own portfolio.
Which has the lower expense ratio, MGK or SPYG?
SPYG currently has the lower expense ratio (0.04% vs. 0.05%).
Can I hold both MGK and SPYG?
You can, but there's little point. MGK and SPYG have a daily return correlation of 0.99 over the past 3.0 years, meaning they move almost in lockstep. Holding both roughly doubles a single bet rather than spreading it — pick whichever wins on cost and liquidity and put the money in one place.
Go deeper on either fund
Full daily-updated metrics, holdings context, and category peers.