The 'Variable Rate Fix': Floating-Rate Income That Rises When the Fed Hikes

The Federal Reserve is expected to do this week what markets had largely stopped pricing: raise rates for the first time since 2023, after August inflation printed hotter than forecast. For an income investor the real worry isn't owning bonds. It's owning the wrong ones — the ones whose price just slid and whose coupon is stuck.

That is the fixed-rate math, and it never changes: when the Fed hikes, a fixed bond's price falls and it keeps paying the same interest. You bought a "safe" income stream and got the downside of a rate move with none of the upside. There is one corner of fixed income engineered to run the other direction. It's the floating-rate note, or FRN, and its entire character comes down to a single, oddly named event: the variable rate fix.

An FRN's coupon is built from two parts. There is a floating benchmark — for Treasury FRNs, tied to the most recent 13-week Treasury bill — plus a fixed spread set when the note is issued. Every reset period, the benchmark is re-measured and the variable coupon is "fixed" for the next stretch: weekly for the Treasury version, quarterly for most corporate FRNs. Because the income chases the benchmark, the price barely needs to move. A floater's duration is roughly the time to its next reset, not five or ten years. Fixed bonds fall in price so their yield rises; floaters simply re-price their coupon upward and hold their price. They convert interest-rate risk into income.

That mechanism matters more now than it has in years. The Fed has been holding the federal funds rate at 3.50%–3.75%, but after the latest CPI reading the market now prices a quarter-point hike to 3.75%–4.00% at the meeting ending September 16, with the probability jumping to nearly 90%. This is the "running it hot" regime made concrete: inflation that will not settle back to 2%, forcing policymakers to tighten again.

Watch what that does to the next fix on the income vehicles built for this. The iShares Floating Rate Bond ETF (FLOT), which holds investment-grade corporate FRNs with maturities under five years at an expense ratio of 0.15%, trades within a few cents of $51 and pays a trailing yield around 4.3%. Each quarter, its holdings' coupons are re-set to whatever the benchmark is plus their spreads — so if the policy rate moves to 3.75%–4.00%, the benchmarks those coupons re-fix to move with it. The credit-risk-free side is similar: iShares Treasury Floating Rate Bond (TFLO) yields roughly 3.75%, resetting purely with the Treasury benchmark. And for a little more income, VanEck's investment-grade floater fund (FLTR) pays about 4.5%. The gap between the ~3.75% Treasury floaters and the ~4.3%–4.5% corporate floaters is the market's price for carrying credit risk.

Now the honest part — what this income is, and what it isn't. The fix moves with the policy rate in both directions. When the cycle eventually turns and the Fed starts cutting, the variable coupon falls too; there is no locked-in rate. The price holds near par rather than rallying, so floaters offer none of the capital-appreciation kick of long bonds when rates fall. And the corporate versions carry credit risk the Treasury versions do not: if the economy breaks, spreads widen and even investment-grade floaters lose value. This is rate-resetting income, not a compounding machine. It protects against a hiking regime; it does not build growing wealth the way a dividend grower does.

For a portfolio, that earns floaters a specific, small role: the all-weather sleeve that offsets the duration risk sitting in your fixed-bond allocation. Between the flavors, the choice is straightforward. Buy TFLO if you want the reset with no credit risk. Buy FLOT or FLTR if you are willing to accept the credit spread for the extra yield. Either way, when the Fed hikes this week, Tuesday's decision becomes next quarter's higher "fix" — one of the few places in fixed income where the news that bruises your bonds works in your favor instead.