Data Sources & Methodology

Last updated: May 2026

QuantStack sources market data from multiple providers to power its screening and backtesting platform. This page documents the sources, coverage, freshness characteristics, and known limitations of each data provider.

1. US Market Data

PrimaryTiingo

Tiingo provides end-of-day (EOD) price data, adjusted close prices, and ticker metadata for US equities. This is the primary data source for all US market screening.

Data Types

EOD prices, dividend-adjusted close, ticker metadata, basic fundamentals

Coverage

S&P 500, Nasdaq 100, Dow 30. Over 4,000 US-listed equities available.

Freshness

EOD data updated by next market day (T+1). Intraday data not available.

2. Thai Market Data

PrimarySETSMART

SETSMART (Stock Exchange of Thailand market data service) provides official EOD prices, company fundamentals, financial statements, and SET/mai listings.

Data Types

EOD prices, P/E, P/BV, EPS, dividend yield, sector classification

Coverage

Full SET and mai listings (~700+ listed companies)

Freshness

EOD data updated by next market day. SET market hours: 10:00–12:30, 14:30–17:00 ICT

FallbackYahoo Finance

Yahoo Finance serves as a fallback data source for Thai equities when SETSMART data is unavailable. Coverage is limited and may exclude smaller listed companies. Fundamental data from Yahoo is less comprehensive than SETSMART.

3. Data Limitations

Important: Read Before Using Data

Data quality limitations exist across all providers. Always verify data independently before making any investment decision.

  • !
    Price delays: EOD prices may be delayed by 15–30 minutes for some providers and subscription tiers. QuantStack does not offer real-time pricing.
  • !
    Fundamental data lag: Financial statement data (earnings, balance sheet, ratios) may lag actual corporate filings by 1–2 quarters depending on reporting schedules and data provider indexing.
  • !
    Corporate actions: Stock splits, dividends, and rights issues are adjusted retroactively where technically possible, but adjustments may not always be current or complete.
  • !
    Delistings and new listings: Recently delisted or newly listed securities may not appear in screener results immediately. Universe updates occur nightly.

4. Backtest Methodology

QuantStack backtests apply quantitative factor models to historical price and fundamental data. All results are strictly hypothetical.

What we do

  • Apply configurable transaction cost profiles (US standard, Thai standard)
  • Use point-in-time data where available to minimize lookahead bias
  • Benchmark returns against SPY, SET TRI, and custom indices
  • Report gross and net-of-cost returns separately

Known limitations

  • Survivorship bias may exist for pre-2015 data
  • Market impact and liquidity not fully modeled
  • Thai tax treatment (0.07% stamp duty) applied but broker fees vary
  • Fundamental data lag may introduce minor lookahead in quarterly rebalances

All backtest output pages include an assumptions summary and investment disclaimer. Hypothetical past performance does not guarantee future results.

5. Model Validation Status

QuantStack maintains a model registry that tracks the validation status, data requirements, and known limitations of each quantitative model available on the platform.

View Model Registry →

6. Provider Terms of Use

Data accessed through QuantStack is subject to the terms of use of the underlying data providers. By using QuantStack, you agree to comply with these terms:

  • Tiingo: Market data is provided for personal research use. Commercial redistribution or bulk download of data obtained through QuantStack without a commercial Tiingo license is prohibited. See tiingo.com/legal.
  • SETSMART (SET): Thai market data is proprietary to the Stock Exchange of Thailand. Redistribution or resale of SETSMART data without authorization from the SET is strictly prohibited. See setsmart.com.