Every comparison report and interactive simulator on StockCat (stockcat.net) is built on reproducible quantitative rules and historical market data.
1. Data Sources
- Equity & ETF Time Series: Historical prices, dividend distributions, and split adjustments are sourced from Yahoo Finance market data feeds.
- Multi-Year Daily FX Database: Currency conversions (KRW, JPY, TWD, EUR vs. USD) use daily historical exchange rates from 2003 to the present.
- ETF Holdings & Expense Ratios: Top constituent weights and Total Expense Ratios (TER) reference official fund disclosures and StockAnalysis.
2. Calculation Rules & Assumptions
- Dividend Reinvestment (DRIP) Total Return: Cash dividends (pre-tax or after-tax depending on your selected toggle) are reinvested into additional shares at the distribution-period price to model compounding share growth.
- Dividend Tax Assumptions: After-tax simulation modes apply standard retail withholding benchmarks (such as 15% US withholding or 15.4% Korean dividend tax). Actual tax liability depends on your residency and account type.
- CAGR (Compound Annual Growth Rate): Annualized geometric return calculated between the initial capital and final portfolio value over the exact holding period.
- Historical FX Backfill (BFILL): For assets predating 2003 (e.g., SPY since 1993), the earliest available exchange rate is backfilled to prevent currency-scale distortion.
3. Quality Control & Limitations
- Tickers missing critical metrics (price, yield, or expense ratio) are filtered out before publishing.
- Backtests reflect historical data and exclude brokerage commissions, bid-ask spreads, and currency conversion fees.