CPAG vs SPAB

CPAGBF/m Compoundr U.S. Aggregate Bond ETF

SPABAState Street SPDR Portfolio Aggregate Bond ETF

In short

CPAG A core U.S. bond fund built to compound rather than pay out. It tracks the Nasdaq Compoundr U.S. Aggregate Bond Index, and income stays inside the fund instead of landing in your account as cash.

SPAB A 2007-vintage core bond fund priced at 0.03%: roughly 8,500 US investment-grade bonds in one ticket, at the same rock-bottom fee the household names charge for the same index.

Stated mandate

CPAG The fund seeks investment results corresponding to the Nasdaq Compoundr U.S. Aggregate Bond Index. It generally uses replication and may use representative sampling when full replication is not practicable.

SPAB The fund seeks to track the price and yield performance of the Bloomberg U.S. Aggregate Bond Index before fees and expenses, providing broad exposure to U.S.-dollar-denominated investment-grade bonds.

Why people hold it

• CPAG Income compounds inside the fund instead of arriving as cash, so there is nothing to reinvest by hand.
• At 0.31% a year, it undercuts the typical fund in the core bond crowd.
• Simple machinery: replicate the index, and sample only when full replication is not practical. No side bets bolted onto the mandate.

• SPAB 0.03% a year against a 0.36% median for its peer group, and the same ticket price as AGG, SCHZ and BBAG on the identical index.
• Roughly 8,500 dollar-denominated investment-grade bonds in one line item, tracking the Bloomberg U.S. Aggregate Bond Index. Diversification you could not assemble bond by bond.ssga.com
• Trades actively and has tracked its index closely, putting it among the stronger implementations in the core-bond group.
• Running since 2007, now a multi-billion-dollar fund, and it pays monthly rather than quarterly.

Worth knowing

• CPAG The 0.03% giants (BND, SPAB, SCHZ) are right there. The compounding wrapper is what the extra fee buys.
• Launched in 2025, still small and thinly traded, so the record is short and spreads can run wider than the mega-Aggs. Limit orders earn their keep.
• Nothing shows up in your account to spend. That is a different rhythm from a core bond fund that pays monthly.

• SPAB Bond prices move opposite yields. When rates rise the index falls and the fund follows it down; a 0.03% fee cannot cushion that.
• AGG, SCHZ and BBAG hold the same declared index at the same 0.03%. Picking among them comes down to spreads and platform, not the portfolio.
• Investment grade and US dollar only by mandate: high yield and foreign-currency debt sit outside the remit.ssga.com

Full CPAG profile⁠

Full SPAB profile⁠