American Century Securitized Credit ETF (ASEC)

The American Century Securitized Credit ETF holds a diversified portfolio of non-agency mortgage-backed securities, collateralized loan obligations, and other asset-backed securitizations—credit instruments built on pools of consumer mortgages, auto loans, and equipment leases that carry real default risk and higher yield than government-backed alternatives.

What exactly is in this fund?

The core holdings are non-agency residential mortgage-backed securities (mortgages that do not carry the implicit guarantee of Fannie Mae or Freddie Mac), collateralized loan obligations layered from auto loans and consumer receivables, asset-backed securitizations from equipment leases and other receivables, and occasionally student-loan securitizations. Each of these is essentially a bond backed by hundreds or thousands of underlying borrower obligations pooled together. A single mortgage-backed security might represent 5,000 mortgages; an auto-loan securitization might pool 50,000 individual loans. The fund buys tranches of these structures, meaning its position sits at a specific layer within the subordination hierarchy — which layer determines how quickly the fund takes losses if borrowers default.

Why does ASEC pay higher yields than Treasury bonds?

The answer is credit risk. A Treasury bond is backed by the U.S. government’s ability to tax and print currency; these securitized credits are backed solely by borrower payments. When borrowers default, investors in the lower tranches absorb the first losses with no federal backstop. Securitized credits therefore carry meaningful default risk, and that risk demands a yield premium — typically several percentage points above Treasury yields of similar maturity. In calm credit environments, that yield premium is a pure income benefit to the fund holder. In recessions or financial stress, the spreads widen sharply and existing bond prices fall because the market reprices credit risk upward.

What are the operating mechanics and costs?

The fund is actively managed, meaning American Century’s team makes tactical decisions about which securitized credits to hold and when to rotate between mortgage securities, auto securitizations, and other asset types. The expense ratio is 0.29 percent annually — modest for a specialty fixed-income strategy, though higher than a passive government bond index. The fund trades on the NASDAQ with decent daily liquidity for retail positions, though large block trades may encounter wider bid-ask spreads depending on market conditions. The fund pays income distribution regularly as underlying loans are paid down and reinvested.

Where does this strategy break down?

Economic recession is the primary threat. Rising unemployment and mortgage delinquencies follow, and defaults on the underlying loans eat into the fund’s value. Because the fund holds no federal guarantee, losses flow directly to shareholders — there is no government rescue like the 2008 mortgage-crisis interventions that cushioned agency mortgage holders. Prepayment risk creates a secondary hazard: when interest rates fall, borrowers refinance, bonds get repaid early, and the fund receives cash that must be reinvested at lower yields. The internal structure of each securitization — which tranches absorb losses first — determines how much impact any given delinquency rate has on the fund’s position. Housing-price declines amplify losses because underwater borrowers are more likely to default. Liquidity also dries up in market stress, forcing sellers to accept wider spreads.

Who typically holds this fund?

Income-seeking investors with moderate-to-high risk tolerance who understand fixed-income mechanics and want yields above government bonds. Experienced fixed-income managers. Professionals familiar with mortgage-market dynamics and willing to monitor unemployment and housing-price trends. Not appropriate for conservative portfolios, capital-preservation mandates, or investors uncomfortable with potential credit losses.

How to research and monitor ASEC?

Start with the prospectus and current fact sheet, which detail the portfolio composition, weighted-average life, duration, and the specific tranches held. Calculate the fund’s current yield and spread over comparable Treasury securities — tight spreads suggest credit is expensive; wide spreads may indicate value opportunity. Examine the fund’s positioning between residential mortgages, auto securitizations, and other assets; this shifts based on market outlook. Track key economic data weekly: unemployment claims, mortgage delinquency rates on underlying borrowers, auto-loan delinquencies, and housing-price trends. Monitor dealer quotes for non-agency mortgage securities (Bloomberg terminals carry these), as dealer inventory and bid-ask spreads often widen before fund price declines. Rising delinquency trends are early warning signals, sometimes appearing weeks before losses show up in the net asset value.