Volatility Clustering in Semiconductor Stock Returns: The Role of ChatGPT Inception, Version Upgrade, and the Launch of the DeepSeek AI Model — A Case Study on NVIDIA, AMD, and Intel
DOI:
https://doi.org/10.7190/fintaf.v3i1.507Abstract
ABSTRACT
This study investigates the impact of major artificial intelligence (AI) milestones, including the inception of ChatGPT (Nov 30, 2022), its subsequent upgrade (May 13, 2024), and the release of the DeepSeek AI model (Jan 20, 2025), on stock return volatility in the global semiconductor industry. Focusing on NVIDIA, AMD, and Intel, the research integrates event study methodology with GARCH-family models (GARCH, EGARCH, DCC-GARCH) to assess volatility clustering, asymmetric responses, and inter-firm spillover effects at the firm level.
Daily stock returns from January 2015 to March 2025 were analysed, with AI-related events categorised by type to capture differential market reactions. Results reveal pronounced volatility clustering in all three firms, with persistence levels highest for Intel. EGARCH estimates confirm asymmetric volatility, showing stronger market reactions to adverse AI-related news, particularly competitive threats such as DeepSeek’s entry. DCC-GARCH modelling indicates significant time-varying volatility spillovers, especially between NVIDIA and AMD, suggesting sector-wide contagion effects during AI innovation cycles.
The findings extend financial market literature by providing firm-level evidence on how AI-driven technological developments influence volatility dynamics within a strategically critical sector. The study offers actionable insights for investors, corporate strategists, and policymakers seeking to navigate innovation-induced risk, while demonstrating the methodological value of combining event study and advanced volatility models for high-tech market analysis.
Keywords: Artificial Intelligence, Volatility Clustering, Asymmetric Volatility, Spillover Effects, GARCH, EGARCH, DCC-GARCH, Event Study, Semiconductor Industry, NVIDIA, AMD, Intel.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Adedeji Adelabu

This work is licensed under a Creative Commons Attribution 4.0 International License.
- It is the responsibility of authors to ensure that permissions to reproduce any kind of third party material are obtained from copyright holders prior to the article being submitted for publication.
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under the CC-BY licence .
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.