Transfer Learning Across Fixed-Income Product Classes
Nicolas Camenzind, Damir Filipovic
TL;DR
This work develops a transfer-learning framework to jointly estimate multiple fixed-income discount curves across product classes by extending kernel ridge regression to a vector-valued RKHS with separable kernels. The approach introduces a graph-regularized norm that promotes smooth spread curves across product classes, and provides a decomposition of the RKHS norm to ensure a valid separable kernel. A Gaussian-process interpretation enables uncertainty quantification and connects KR estimators to posterior means. Empirically, the method improves extrapolation in data-sparse regions—demonstrated via a masking experiment using US government bonds and SOFR swaps—while preserving fit quality in well-sampled regions, with practical implications for multi-currency pricing and cross-product risk assessment.
Abstract
We propose a framework for transfer learning of discount curves across different fixed-income product classes. Motivated by challenges in estimating discount curves from sparse or noisy data, we extend kernel ridge regression (KR) to a vector-valued setting, formulating a convex optimization problem in a vector-valued reproducing kernel Hilbert space (RKHS). Each component of the solution corresponds to the discount curve implied by a specific product class. We introduce an additional regularization term motivated by economic principles, promoting smoothness of spread curves between product classes, and show that it leads to a valid separable kernel structure. A main theoretical contribution is a decomposition of the vector-valued RKHS norm induced by separable kernels. We further provide a Gaussian process interpretation of vector-valued KR, enabling quantification of estimation uncertainty. Illustrative examples show how transfer learning tightens confidence intervals compared to single-curve estimation. An extensive masking experiment demonstrates that transfer learning significantly improves extrapolation performance.
