SPMB — State Street SPDR Portfolio Mortgage Backed Bond ETF

SPMB Price Performance — Growth of $10,000

Value of a $10,000 investment in SPMB over time, compared with SPY. Both lines are rebased to $10,000 on the first shared date. Based on total returns — prices are adjusted for dividends and splits, so this assumes distributions were reinvested. Hover or tap the chart for exact values.

SPMB Drawdown

The "underwater" chart: SPMB's decline from its highest prior value at each point in time. It shows how deep past losses ran and how long the fund took to recover to break-even.

Overview

The State Street SPDR Portfolio Mortgage Backed Bond ETF (SPMB) is a Mortgage-Backed category fund managed by State Street Investment Management. With $7.07 billion in assets under management and a trading price of $22.01, the fund demonstrates significant investor adoption relative to its peers. It holds an overall rank of #284 out of 458 tracked ETFs across all categories, earning an ETFValuer grade of C with a score of 58.3 out of 100. The fund offers a low-cost structure with an expense ratio of 0.04% and provides a dividend yield of 4.07%. It operates within a category containing 4 ETFs tracked by ETFValuer. The combination of high assets and a mid-tier rank suggests a established position within the sector despite the moderate overall rating. Its cost profile and yield characteristics align with typical fixed-income exposure in the mortgage-backed space.

Short-term performance shows mixed results with a 1-day decline of -0.41% followed by a slight 1-week gain of +0.09%. The fund experienced negative returns over the first three months, dropping -1.47% in one month and -0.85% over three months, while the six-month return sits at -0.54%. Year-to-date performance has turned positive with a gain of +0.17%, contrasting with the earlier negative trends. Over the past year, the fund generated a return of +4.87%, which compares to peer MBB at +4.69% and VMBS at +4.80%. The three-year return stands at +15.49%, indicating a longer-term positive trajectory despite recent short-term volatility. The data reveals a divergence where short-term periods show weakness while the one-year and three-year horizons reflect positive accumulation.

The fund carries a volatility label of Very Low, yet it exhibits a beta of 1.15, suggesting it moves more than the broader market despite the low volatility classification. A Sharpe ratio of -0.03 indicates that the risk-adjusted returns have been minimal or negative relative to the risk taken over the measured period. The maximum drawdown of -6.93% represents the largest peak-to-trough decline experienced by the fund. This combination of a negative Sharpe ratio and a defined maximum drawdown implies that while the fund may not experience extreme daily swings, it has faced periods where returns did not adequately compensate for the downside risk. The beta above 1.0 suggests sensitivity to market movements that contrasts with the low volatility label, creating a complex risk profile for investors.

AI-generated summary based on the data on this page.

SPMB Top Holdings

Holdings as of 2026-03-31 per the fund's most recent SEC N-PORT-P filing. Top 10 holdings make up 13.6% of net assets — a rough gauge of concentration risk (the higher this figure, the more the fund's return depends on a handful of names). To see how SPMB's holdings overlap with other ETFs you own or are considering, check the Stock Overlap tool.

Which Funds Overlap With SPMB

Holding two funds that own the same companies adds cost and complexity without adding much diversification. These tracked ETFs share the most names with SPMB's top 10 — MBB overlaps most, holding 4 of the same companies as SPMB's top 10 (6.2% of SPMB's assets).

Compares the top 10 reported holdings of each fund, so it's a floor on true overlap — two S&P 500 trackers overlap ~100% even when only 10 names are listed. Use the Stock Overlap tool to search by individual company.

Market Backdrop

10-Year Treasury Yield: 4.61% (as of 2026-07-28) — The yield on 10-year US Treasury bonds — the standard "risk-free rate" benchmark used to contextualize this fund’s Sharpe ratio and returns.

CBOE Volatility Index (VIX): 18.21 (as of 2026-07-28) — A real-time gauge of expected S&P 500 volatility over the next 30 days — useful context for this fund’s own volatility label.

Federal Funds Rate: 3.63% (as of 2026-06-01) — The Federal Reserve’s target policy rate, which anchors short-term borrowing costs across the economy.

SPMB Liquidity, Domicile & Tax Treatment

Liquidity: Quoted bid/ask spread is 0.00% and average daily volume is 1.3M/day. Tighter spreads and higher volume mean lower round-trip trading costs; this is a live-market snapshot and can widen during volatile sessions. AUM of $7.07B provides ample scale, supporting tight spreads and issuer commitment to keep the fund open.

Domicile & tax treatment: SPMB is a US-domiciled, SEC-registered ('40 Act) exchange-traded fund. Dividends and capital gains distributions are reported to US investors on Form 1099-DIV, and the fund is not subject to the PFIC reporting or UCITS-specific rules that apply to Irish- or Luxembourg-domiciled funds. Non-US investors should note that US-domiciled ETFs are generally subject to 30% US withholding tax on dividends (unless reduced by treaty) and to US estate tax exposure on the position — Irish-domiciled UCITS ETFs tracking the same index often avoid both, which is why non-US residents frequently prefer the UCITS equivalent where one exists. This is general information, not tax advice — consult a tax professional for your situation.

SPMB Performance History

How SPMB Compares to Other Mortgage-Backed ETFs