Frequency Matters: When Time Series Foundation Models Fail Under Spectral Shift

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Wang, Tianze, Ennadir, Sofiane, Pertoft, John, Gandler, Gabriela Zarzar, Cao, Lele, Senane, Zineb, Katsarou, Styliani, Asadi, Sahar, Karlsson, Axel, Smirnov, Oleg
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866908637844209664
author Wang, Tianze
Ennadir, Sofiane
Pertoft, John
Gandler, Gabriela Zarzar
Cao, Lele
Senane, Zineb
Katsarou, Styliani
Asadi, Sahar
Karlsson, Axel
Smirnov, Oleg
author_facet Wang, Tianze
Ennadir, Sofiane
Pertoft, John
Gandler, Gabriela Zarzar
Cao, Lele
Senane, Zineb
Katsarou, Styliani
Asadi, Sahar
Karlsson, Axel
Smirnov, Oleg
contents Time series foundation models (TSFMs) have shown strong results on public benchmarks, prompting comparisons to a "BERT moment" for time series. Their effectiveness in industrial settings, however, remains uncertain. We examine why TSFMs often struggle to generalize and highlight spectral shift (a mismatch between the dominant frequency components in downstream tasks and those represented during pretraining) as a key factor. We present evidence from an industrial-scale player engagement prediction task in mobile gaming, where TSFMs underperform domain-adapted baselines. To isolate the mechanism, we design controlled synthetic experiments contrasting signals with seen versus unseen frequency bands, observing systematic degradation under spectral mismatch. These findings position frequency awareness as critical for robust TSFM deployment and motivate new pretraining and evaluation protocols that explicitly account for spectral diversity.
format Preprint
id arxiv_https___arxiv_org_abs_2511_05619
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Frequency Matters: When Time Series Foundation Models Fail Under Spectral Shift
Wang, Tianze
Ennadir, Sofiane
Pertoft, John
Gandler, Gabriela Zarzar
Cao, Lele
Senane, Zineb
Katsarou, Styliani
Asadi, Sahar
Karlsson, Axel
Smirnov, Oleg
Machine Learning
Artificial Intelligence
Time series foundation models (TSFMs) have shown strong results on public benchmarks, prompting comparisons to a "BERT moment" for time series. Their effectiveness in industrial settings, however, remains uncertain. We examine why TSFMs often struggle to generalize and highlight spectral shift (a mismatch between the dominant frequency components in downstream tasks and those represented during pretraining) as a key factor. We present evidence from an industrial-scale player engagement prediction task in mobile gaming, where TSFMs underperform domain-adapted baselines. To isolate the mechanism, we design controlled synthetic experiments contrasting signals with seen versus unseen frequency bands, observing systematic degradation under spectral mismatch. These findings position frequency awareness as critical for robust TSFM deployment and motivate new pretraining and evaluation protocols that explicitly account for spectral diversity.
title Frequency Matters: When Time Series Foundation Models Fail Under Spectral Shift
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2511.05619