An interpolation scheme has interpolation locality if a change in one input quote changes the curve only near that input’s maturity. Locality decides what a bucketed hedge looks like: under a local scheme an off-pillar swap is hedged with the pillars around it; under a non-local one it acquires risk, of either sign, on pillars far from its maturity.
Exemples
Example 1.12 (An eight-year swap on four curves)
A par payer swap of USD 100 million for eight years has a parallel DV01 of about USD 69 600 on all four curves: they agree on the level. They disagree on where it sits (Figure 1.5). Flat forwards put USD 40 400 on the seven-year quote and USD 29 200 on the ten-year; the cubic spline puts USD 62 100 on seven years, on five, on four and on twelve; monotone convex lies in between. Each set of buckets sums to the parallel DV01, and each asks for a different hedge.