About Jeff
I'm Jeff. For more than 20 years my job has been international tax: serving multinational groups on cross-border investment structures, group reorganizations, and in recent years the hottest topic in tax, the OECD Pillar Two global minimum tax.
I have also invested in US stocks for years, holding twenty-plus individual names and ETFs. My habit when a 10-K lands differs from most investors: they go to EPS first, I turn to the income tax footnote. A one percentage point move in the effective tax rate often says more about earnings and valuation than whatever narrative the market is trading that week.
The third pillar is AI and automation. I apply professional judgment to decide the key next step, then direct AI to generate the code (Python) that pulls SEC EDGAR and market data, deep-read filings and regulations with AI tools, and run a multi-source verification protocol that keeps AI hallucination out of the output. The code is AI-generated; the value is my judgment. With the research workflow automated, one person can produce close to team-level work. For what this looks like in practice, I wrote up a hands-on case.
Background
| Dimension | Detail |
|---|---|
| Practice | 20+ years in international tax: accounting firm tax practice + in-house tax at a foreign bank, serving multinational groups |
| Academic | MS in Finance (Aston University, UK) + MS in Accounting (National Chengchi University, Taiwan) + BA in Accounting (National Chengchi University, Taiwan) |
| Credentials | Passed the Taiwan CPA examination + internal auditor certification |
| Specialization | Global minimum tax (OECD Pillar 2), cross-border investment tax planning, AI-automated tax and investment analysis |
| Investing | US individual stocks + ETF portfolio, long-term holdings |
| AI & Automation | AI research workflow design, directing AI to generate automation code (SEC EDGAR, yfinance data pulls), multi-source verification |
| Languages | Traditional Chinese + English, bilingual |
What this site covers
- Deep dives into the tax structures of major US companies (where Apple's, Google's, and Microsoft's ETRs actually come from)
- Cross-border tax essentials for non-US investors in US stocks (estate tax, dividend withholding, ADR mechanics)
- How the Pillar Two global tax reform hits US tech stocks
- Hedge fund 13F tracking and analysis methods
- Using AI to automate the investment research workflow
Writing principles: every number carries a source and a date, every case states its assumptions, and everything AI-assisted passes human review and multi-source fact-checking. Professional content is only worth reading if it can be trusted; that part is not negotiable.
Some topics also come as short videos on the YouTube channel (Chinese-language), for readers who want the one-minute version first.