The yield curve plots every priced conventional gilt and fits a line through them; reading one gilt against that line is the question the page exists to answer.
The yield curve is one picture of the whole conventional market: every priced gilt plotted at its own yield against its remaining term, with a curve fitted through the points. A single gilt read against that line is what the page is for — is this gilt cheap or dear for its maturity?
What the line is
The fit is a Nelson-Siegel-Svensson curve through the day's priced conventional gilts, drawn as a par yield: the coupon a new gilt of that maturity would need to trade at 100. A gilt whose point sits above the line yields more than its neighbours imply; one below yields less.
The gilts in the fit are the ones the report priced. A gilt the pipeline skipped is still plotted as a point and left out of the fit. Fitted yields at the very short and very long ends are the model's extrapolation rather than any gilt's own yield, which is why the curve can extend past the last point on the chart.
Working the page
- Open the curve from the nav.
- Set the report date in the page head and press Apply if you want a day other than the latest stored report.
- Choose Par or Zero-coupon. The par view is the coupon a new gilt would need; the zero-coupon view discounts a single payment at each term and is where the coupon effect drops out.
- Read the key rates above the chart — the 2, 5, 10 and 30-year points — as the short summary of the same line.
- Read a gilt's point against the line at its own term, and open the gilt from the list to see the same comparison in numbers.
The same comparison in figures
A gilt's own page carries Vs fitted curve: the gap between its yield and the fitted curve at its maturity, in basis points, signed. Positive means the gilt yields more than the line at that term; negative means less. That is exactly the vertical distance from the point to the curve on the chart, so the two views cannot disagree — they are computed from one stored curve.
The same page carries the gilt's price and yield history, so a gap can be read against where it has been rather than on one day alone. The list is the way in: open any gilt from it.
The three related pages
- The RPI curve — the index-linked market plotted the same way, at real yields.
- The comparison — the two curves side by side, for the gap between the nominal and real market at each term.
- Attribution — what moved the curve, so a shift can be read as a change of shape rather than one number.
Two empty states, and what they mean
Why do the key rates show “Too few on-curve gilts”?
The 2Y/5Y/10Y/30Y key-rate tiles are interpolated between the priced conventional gilts that sit on the fitted curve, using each gilt's benchmark yield — or its own gross yield when the report carries no benchmark data. A tenor needs at least one on-curve gilt maturing before it and one after it to interpolate. On a day when too few gilts are priced, or all of them sit on one side of the tenor, no pair brackets it, so the site skips that tile with the note rather than inventing a number.
Curve unavailable for this report
The curve itself has a related state: when fewer than three priced conventional gilts are in the fit, the page says the curve is unavailable for that report and plots the points anyway, because each point is that gilt's own gross redemption yield and needs no fit to be true.
What the chart is not
A gilt above the curve is not a bargain and one below is not a mistake. The gap describes where the market has priced that gilt relative to the fitted line on one report date, and it says nothing about what the gilt will return. The gilt's own page carries the figures that do: the yields, the cash flows and the points against both curve bases.
Prices and yields are mid, per £100 nominal, from one report date, and every figure assumes a T+1 settlement. The terms this page draws on are the glossary's gross-yield, real-yield, npv-par-curve and npv-zero-coupon.