Which of the following instruments is expected to be the most stable if rates rise significantly in the next one to two years?

Treasury notes have longer maturities, typically ranging from two to ten years, which makes them more sensitive to changes in interest rates. If rates rise, the prices of existing Treasury notes will decline more significantly than T-bills, leading to greater instability and potential losses for investors holding these instruments.

Long-term insured municipal bonds are also vulnerable to interest rate increases. Their longer durations mean that when rates rise, the present value of future cash flows diminishes more sharply, causing a decline in their market prices, which compromises their stability compared to T-bills.

Similar to long-term municipal bonds, investment grade corporate bonds have extended maturities and are therefore subject to greater price volatility when interest rates rise. This market sensitivity can lead to significant capital losses, which makes them a less stable option during periods of anticipated rate increases.