It tracks a US Treasury principal STRIPS index, with most of its portfolio invested in ultra-long-term US Treasury principal STRIPS with remaining maturities of 25 years or more.

It suits institutions and investors who want an aggressive bet on falling interest rates, or who need a precise hedge against long-term liabilities.

It is a passively managed (index-tracking) ETF launched by PIMCO in 2009.

The fund holds only zero-coupon bonds that pay no interest (coupons), which maximizes duration. This drives much steeper price gains than ordinary bonds when rates fall, and the absence of reinvestment risk is a key strategic feature.

• Interest rate sensitivity (duration) among the highest in the industry
• Reinvestment risk eliminated through the zero-coupon structure

Assets under management (AUM) stand at $1.9B, and the Expense Ratio is 0.15% per year.

Its duration is far longer than that of TLT, the best-known long-term Treasury ETF, so both the shock and the gains from interest rate moves are amplified.

Buying has flowed into ultra-long-term bond assets on expectations of global rate cuts and signs of cooling inflation, and prices are trying to rebound, but volatility remains high.

As the view that rates have peaked spreads, speculative demand seeking to maximize capital gains and hedging demand to protect long-term portfolios are rising at the same time, and trading volume is becoming more active.

Its main feature is the high leverage effect when interest rates fall, but conversely it carries the risk of a severe decline in asset value when rates rise.

TLT and VGLT, shown in the table, are conventional long-term Treasury ETFs that pay coupons and have relatively lower volatility than ZROZ. If you want even more extreme duration, you can also consider EDV, and if you prefer a somewhat shorter maturity range, TLH is an option to review. If you need an inverse strategy to prepare for rising rates, a product such as TBT could be an alternative.

These are the key points to review before investing in ZROZ. Investors should recognize that this product goes beyond simple bond investing and resembles a sophisticated interest rate derivatives strategy.

Ultra-long-term bonds react very sensitively to changes in macroeconomic indicators, so when economic data differs from market expectations, returns can swing by double digits in a single day.

It is an effective strategic tool for aggressive investors seeking large capital gains in a rate-cutting cycle, but it must be accompanied by thorough risk management that can withstand the equally harsh volatility.