MBB vs SPY
iShares MBS ETF vs State Street SPDR S&P 500 ETF Trust
Which is better, MBB or SPY?
SPY has been ahead.
MBB has a lower expense ratio. SPY led over 1Y, 3Y, 5Y and the full window.
MarketXLS is not an investment adviser. This comparison is generated automatically from market data and is for information only. A Best mark means the better reading on that one measure, not a recommendation to buy.
Side-by-Side Comparison
| Metric | MBB | SPY |
|---|---|---|
| Expense Ratio | 0.04%Best | 0.09% |
| AUM | $39.4B | $804.7B |
| Dividend Yield | 4.34% | 0.98% |
| Holdings | 11,186 | 505 |
| YTD Return | -1.36% | +11.97%Best |
| 1Y Return | -0.56% | +16.40%Best |
| 3Y Return (annualized) | +4.39% | +21.10%Best |
| 5Y Return (annualized) | -0.16% | +12.88%Best |
| Volatility (annualized) | 4.3%Best | 15.5% |
| Max Drawdown | -18.4%Best | -56.5% |
| $10,000 over 5 years | $9,920 | $18,327Best |
| Fund Family | iShares by BlackRock (US) | State Street Investment Management |
| Category | Fixed Income | Equity |
| Style | - | Large Cap Blend |
| Inception | Mar 13, 2007 | Jan 22, 1993 |
Not shown on this pair: Top 10 Weight.
Volatility and max drawdown are measured over the window both funds cover: Mar 16, 2007 to Sep 14, 2026 (19.5 years).
MBB vs SPY growth
Month-end closes. Both lines start at 0% in the first month shown, so the gap between them is the difference in growth across that window. The full view is available from the range buttons; it is not the opening view here because over the whole period one of these two funds moves so much further than the other that its line would sit flat on the axis.
MBB vs SPY Performance
iShares MBS ETF (MBB) is an ETF from iShares by BlackRock (US) and State Street SPDR S&P 500 ETF Trust (SPY) is an ETF from State Street Investment Management. Over the past year MBB returned -0.56% while SPY returned +16.40%. Year to date, MBB is down 1.36% versus a gain of 11.97% for SPY.
Over three years, MBB compounded at +4.39% per year against +21.10% for SPY; over five years the annualized figures are -0.16% and +12.88% respectively. Across the full 20-year window we track, SPY has the edge at +9.54% annualized vs +0.39%.
Past performance does not guarantee future results.
Risk: Volatility and Drawdowns
SPY has been the more volatile fund, with annualized monthly volatility of 15.5% compared with 4.3% for MBB. Lower volatility generally means a smoother ride, though it often comes with lower long-run returns.
The deepest peak-to-trough decline in our data was -18.4% for MBB and -56.5% for SPY. Drawdown depth is what each fund did in the worst stretch of the window measured above.
The two funds' monthly returns correlate at 0.21. They move largely independently of each other.
Fees and Cost Over Time
MBB charges 0.04% per year while SPY charges 0.09%. On a $10,000 position that is $4 vs $9 annually, a gap of $5 per year that compounds over a long holding period. On income, MBB currently yields 4.34% against 0.98% for SPY.
Holdings Overlap
We hold position weights for 8,260 holdings in MBB and 504 in SPY, totalling 90.9% and 99.9% of the two funds. The two books name no position in common, so there is no overlap percentage to show.
0 positions in common, counted across the 8,260 positions we hold weights for in MBB and 504 in SPY, against full books of 11,186 and 505.
You are not choosing between two funds in isolation.
Whichever of MBB and SPY you pick has to sit alongside everything else you own. Add the rest and see what the combination actually holds.
Free for up to 10 holdings. No account needed.
Frequently Asked Questions
Which is cheaper, MBB or SPY?
MBB has an expense ratio of 0.04% while SPY charges 0.09%. MBB is the cheaper option, by $5 a year on a $10,000 investment.
Which performed better, MBB or SPY?
Over the past year MBB returned -0.56% vs +16.40% for SPY, so SPY leads on 1-year performance. Over the longest common window we track (20 years), MBB annualized +0.39% vs +9.54% for SPY. Past performance does not guarantee future results. This is information, not a recommendation.
Which is riskier, MBB or SPY?
SPY has been the more volatile fund at 15.5% annualized versus 4.3% for MBB. Worst drawdown: MBB -18.4% vs SPY -56.5%.
Should I hold both MBB and SPY?
MBB and SPY have a monthly-return correlation of 0.21, so their returns are far enough apart for the mix to behave differently from either one alone. This is information, not a recommendation.
Which pays a higher dividend, MBB or SPY?
MBB yields 4.34% while SPY yields 0.98%, so MBB currently pays the higher dividend yield.
Is SPY better than MBB?
MBB has a lower expense ratio. SPY led over 1Y, 3Y, 5Y and the full window. Which one suits a particular account depends on what it is for. This is information, not a recommendation.