Latent Structural Similarity Networks for Unsupervised Discovery in Multivariate Time Series
Olusegun Owoeye
TL;DR
The paper addresses unsupervised relational discovery in high-dimensional multivariate time series by proposing latent structural similarity networks. It combines rolling-window representations learned via a sequence-to-sequence LSTM autoencoder with aggregation to per-entity embeddings, then constructs a sparse similarity graph through a cosine similarity threshold in latent space. Key findings on hourly cryptocurrency returns show non-uniform latent structure with 64 edges at a $\tau=0.90$ threshold, of which 16 pairs satisfy Engle–Granger cointegration, illustrating both linear and non-linear types of relationships. The approach provides a domain-agnostic, interpretable discovery layer that isolates relational structure from predictive objectives, enabling flexible, post-hoc analyses across diverse multivariate temporal domains.
Abstract
This paper proposes a task-agnostic discovery layer for multivariate time series that constructs a relational hypothesis graph over entities without assuming linearity, stationarity, or a downstream objective. The method learns window-level sequence representations using an unsupervised sequence-to-sequence autoencoder, aggregates these representations into entity-level embeddings, and induces a sparse similarity network by thresholding a latent-space similarity measure. This network is intended as an analyzable abstraction that compresses the pairwise search space and exposes candidate relationships for further investigation, rather than as a model optimized for prediction, trading, or any decision rule. The framework is demonstrated on a challenging real-world dataset of hourly cryptocurrency returns, illustrating how latent similarity induces coherent network structure; a classical econometric relation is also reported as an external diagnostic lens to contextualize discovered edges.
