MTGP vs SPMB

MTGPCWisdomTree Mortgage Plus Bond Fund

SPMBAState Street SPDR Portfolio Mortgage Backed Bond ETF

In short

MTGP Most mortgage ETFs are index machines bolted to agency pass-throughs. MTGP is the active counterpunch: a manager picking across mortgage and other securitized debt, hunting income and price gains, and paying out monthly.

SPMB The no-frills way to own America's mortgage bonds. SPMB tracks the Bloomberg U.S. MBS Index for four basis points, a fraction of what the typical mortgage-bond ETF charges, and pays income monthly.

Stated mandate

MTGP The fund is actively managed and seeks income and capital appreciation by investing in mortgage-related debt and other securitized debt.

SPMB The fund seeks to track, before fees and expenses, the price and yield performance of the Bloomberg U.S. MBS Index.

Why people hold it

• MTGP Actively managed, not index-bound. The mandate reaches beyond plain agency paper into mortgage-related and other securitized debt, so a manager sets the mix instead of a benchmark.wisdomtree.com
• Pays monthly, which suits investors who want mortgage-bond income arriving on a regular cadence rather than quarterly.
• Spreads its bets across a couple hundred securitized positions, so no single pool or deal dominates the book.
• Running since 2019 under WisdomTree, giving the active approach a multi-year track record through a brutal stretch for mortgage bonds.

• SPMB Four basis points a year, against a 0.35% median for mortgage-bond ETFs. Cost is where this fund does its loudest talking.
• Runs the same Bloomberg U.S. MBS Index as iShares' MBB at the same 0.04% fee, and undercuts MBBA, which tracks that index for far more.
• Roughly 2,700 mortgage bonds in a single line item, inside a multi-billion-dollar fund that trades actively, with distributions paid monthly.
• Trading since 2009, and one of the strongest implementations in its mortgage-bond peer group.

Worth knowing

• MTGP Active costs money: 0.45% a year, while index rivals like VMBS (0.03%) and SPMB (0.04%) charge a sliver of that. The manager has to out-earn the gap.
• Thinly traded and modest in size, so spreads can be wider than the giant index MBS funds and large orders may need care.
• On our combined read of cost, tradability and mandate delivery, it lands in the lower half of the mortgage-bond ETF pack.

• SPMB Homeowners refinance when rates fall, so mortgage bonds get paid back early and rally less than Treasuries. That quirk is built into the index, not the fund.
• Prices move with interest rates and the monthly payout floats with the portfolio. This is a bond fund, not a cash substitute.
• US mortgages only. No Treasuries, no corporates, no credit spice. A building block for a bond sleeve rather than the whole sleeve.

Full MTGP profile⁠

Full SPMB profile⁠