What it means
When banks trust each other, they lend at rates barely above the risk-free government. When fear arrives, the gap between those rates widens, and that gap is the TED spread.
The name is the parts: T for Treasury bills, ED for Eurodollars, the dollar deposits banks lend each other offshore, and the spread between the three-month rates of each. The Minneapolis Fed's account of the measure explains its logic: Treasuries price time, interbank rates price time plus bank credit risk, so the difference isolates the fear.
Calm markets run tight: in quiet decades the spread lived within a fraction of a percent, a number only money-market desks watched. Crisis makes it famous: in 1987 it jumped on the crash, in 2007-08 it blew out to several hundred basis points as banks hoarded cash and refused each other's paper.
The modern successor is a family: LIBOR's death replaced the classic TED with SOFR-based spreads and the FRA-OIS gap, but the thermometer reads the same fever. For practitioners the spread is an early-warning line: a widening TED says banks see risk in each other before the equity market believes it, and funding costs follow.
For a non-finance reader, the TED spread is the insurance premium on banks lending to banks: cheap when the neighborhood is safe, and the first price to spike when it is not. Market historians keep a small museum of the spread's famous readings, from the 1987 crash to the near-paralysis of 2008.
Each episode widened fast, peaked when policy turned, and then narrowed slowly as guarantees and liquidity rebuilt trust. The pattern repeats so reliably that desks treat the shape of the spread as seriously as the level.
In practice
Real-world examples.
Example
A thirty-basis-point calm ends when a lender fails and the spread gaps past one hundred first.
Example
The 2008 spread neared three hundred basis points, pricing a market that had stopped believing names.
Example
Guarantees that made interbank lending near-sovereign were what finally narrowed the fever.
Formula
Calculation
TED spread equals the three-month interbank (Eurodollar/LIBOR, historically) rate minus the three-month Treasury bill rate, quoted in basis points; dozens of basis points is calm, hundreds is crisis. Readings are reported continuously by market data services and central bank research desks.
Worked example (illustrative figures). In a calm market the three-month interbank rate is 2.50% and the three-month Treasury bill rate is 2.20%, so the spread is 2.50% - 2.20% = 0.30%, which is 30 basis points. In a stressed market the interbank rate jumps to 4.60% while the Treasury bill rate falls to 1.60% as investors flee to safety, so the spread is 4.60% - 1.60% = 3.00%, or 300 basis points. The same bank-credit premium has grown tenfold, from 30 to 300 basis points, even though neither rate on its own tells that story.Case study
Seen in the real world.
This case study is fictional and illustrative. A made-up bank treasurer keeps the TED spread on the corner of her desk monitor through a long calm: it sits near thirty basis points for years, and new analysts ask why she wastes the screen space. The answer arrives in a single quarter: a mortgage lender fails, interbank bids thin, and the spread gaps past one hundred before the equity indices have finished their first bad week. Her funding desk's playbook, written from 2008's scar tissue, triggers automatically: term out the bank's own borrowing now, while the window is open, because a spread at two hundred prices a market that has stopped believing names. The weekly asset-liability meeting watches the thermometer together: the spread peaks near three hundred as rescues are announced, and only narrows when guarantees make interbank lending nearly sovereign again.
The treasurer's teaching session for the new analysts afterwards is the spread's biography: it is one number built from two prices, and it has called every modern banking panic early because it measures the one thing panic is made of, banks' opinion of banks. The screen space is never questioned again, and the new hires learn to check the fever chart before the weather. Her desk's final lesson from the episode is procedural: the thermometer is only useful if someone is paid to watch it daily. She assigns the spread a permanent owner on the funding team, with authority to escalate when it moves, so the next fever is caught on day one instead of week three.
Watch out
Common mistakes.
- Reading it as a stock signal; the TED spread measures bank funding fear, and equities often follow late rather than lead.
- Assuming it still uses LIBOR; the classic construction retired with the benchmark, and SOFR-era cousins carry the same information.
- Treating a level as a crisis; the spread's jump and persistence matter more than any single absolute reading.
Questions
People also ask.
What is the TED spread?
The difference between three-month interbank lending rates and three-month Treasury bills, isolating the market's price of bank credit risk.
Why does it matter?
It widens when banks distrust each other, making it an early-warning gauge of financial stress, as in 1987 and 2008.
Does it still exist after LIBOR?
The exact construction retired with LIBOR, but SOFR-based spreads and FRA-OIS measure the same bank-credit premium.
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