Home Backtesting Guide Historical Data Sources for Backtesting Strategies

Historical Data Sources for Backtesting Strategies

Backtesting is a crucial component of developing and refining trading strategies. It involves testing a strategy against historical data to evaluate its performance and potential profitability. Historical data, which provides a record of past market prices and other relevant information, is essential for accurately simulating trades and assessing the viability of a strategy. In this article, we will explore the importance of historical data in backtesting, where to find reliable data sources, different methods of backtesting, the application of historical data to improve trading strategies, and the challenges and considerations in using historical data for backtesting.

Table of contents:

The Best Historical Data Provider List

Data ProviderWhat They Offer
AlgoseekHistorical US stock and options tick data
FinageReal-time and historical financial data for global markets
Theta DataHistorical and real-time options data
EOD Historical DataHistorical stock, futures, forex, and options data
OratsOptions analytics and trading signals
Whale Wisdom13F filings and hedge fund holdings data
PolygonReal-time cryptocurrency market data
Trading EconomicsMacroeconomic indicators and forecasts
IntrinioFinancial data APIs for stocks, bonds, commodities, and more
CRSPHistorical US stock and mutual fund data
S&P Capital IQFinancial research and analysis tools
FactSetFinancial data and analytics software
EstimizeEarnings estimates from buy-side analysts
ExtractAlphaAlternative data for quantitative investors
IVolatilityOptions analytics and trading signals
CryptoquoteCryptocurrency market data APIs
TraderMadeForex market data APIs
MetaStockTechnical analysis software for traders
Financial Modeling PrepFinancial data APIs for stocks, ETFs, forex, and cryptocurrencies
Investing.comFinancial news, analysis, and tools for traders
eSignalReal-time stock, futures, forex, and options data
CQGTrading software for futures traders
SIXReal-time global market data feeds
CambridgeFISFinancial information services for institutional investors
FinnhubReal-time stock, forex, and cryptocurrency market data APIs
QuandlAlternative financial and economic datasets
XigniteCloud-based financial market data APIs
Intrinio Fintech MarketplaceFinancial data APIs for fintech developers
Barchart Market Data SolutionsReal-time global market data feeds and APIs
Quotemedia Market Data SolutionsReal-time global market data feeds and APIs
Tick Data Market Data SolutionsHistorical futures, options, equities, and forex tick-by-tick data feeds
Kinetick Market Data SolutionsReal-time global market data feeds for NinjaTrader trading software users
dxFeed Market Data SolutionsReal-time global market data feeds for institutional traders and investors
Rithmic Market Data SolutionsLow-latency futures trading platform with real-time market data feeds
CME Group Market Data SolutionsFutures market data feeds from the CME Group exchange
ICE Data Services Market Data Solutions
Yahoo Finance
Google Finance
Global exchange-traded derivatives pricing and analytics tools
Free downloads for stock and ETF data
Free downloads for stock and ETF data

But we save the best providers to the end: Norgate, which only offers end of day data.

The database comprises an extensive array of historical market data sources, encompassing:

  1. High-granularity and real-time forex data.
  2. Comprehensive options and futures market data from nearly all major exchanges.
  3. Market data on government and corporate bonds from multiple countries.
  4. Data on ETFs, Mutual Funds, and even Closed Funds from across the world.
  5. Single stock, fundamental, and equity market data from global exchanges.
  6. Cryptocurrency data from all exchanges, including information on cryptocurrencies that have ceased to exist (survivorship bias).
  7. Alternative datasets, such as social media sentiment, satellite imagery, 13F filings, and web articles.
  8. ESG (Environmental, Social, and Governance) data from a variety of sources.

What is backtesting and why is historical data important?

Everyone understands the concept that garbage in equals garbage out. This is very true for backtesting.

Understanding the concept of backtesting trading strategies

Backtesting refers to the process of evaluating a trading strategy by simulating trades using historical market data. It allows traders to assess how a particular strategy would have performed in the past, which can provide valuable insights and help inform future trading decisions.

The significance of historical data for backtesting

Historical data serves as the foundation for backtesting. It provides the necessary information for traders to analyze and evaluate a strategy’s performance. By using historical data, traders can assess the profitability, risk, and feasibility of a strategy before executing it in a live trading environment.

Hence, you need to pay attention to the data in your models. For example, free data from Yahoo!finance might be useful for backtests that involve the open and the close, but might contain lots of errors if you rely on the low and the high.

We have covered the importance of good data when backtesting in another article.

How historical data impacts trading strategies

Historical data plays a crucial role in the development and optimization of trading strategies. It allows traders to identify patterns and trends, test different approaches, and refine their strategies based on historical market conditions. By using historical data, traders can make more informed decisions and potentially increase their chances of success in the markets.

Where can you find reliable historical data for backtesting?

Using market data from reputable sources

One of the best sources of historical data for backtesting is market data provided by reputable financial data providers. These providers collect and store extensive historical data for various financial instruments, including stocks, currencies, and commodities. They offer comprehensive and accurate data that traders can rely on for their backtesting needs.

Utilizing stock exchange data for backtesting

Stock exchanges also provide historical data that traders can use for backtesting. Many stock exchanges offer access to their historical trade and price data, allowing traders to analyze past market conditions and simulate trades accordingly. This can be particularly useful for traders focused on stocks and equities.

Exploring historical data provided by brokers

Brokers often provide access to historical data for the financial instruments they offer. This data may include historical price data, volume data, and other relevant information. Traders can use this data to backtest their strategies and evaluate their performance in the context of specific brokers and trading platforms.

What are the different methods of backtesting a strategy?

The basics of manual backtesting

Manual backtesting involves manually reviewing historical data, analyzing charts, and simulating trades based on past market conditions. While this method can be time-consuming, it allows traders to gain a deep understanding of their strategies and the impact of different market scenarios.

Automating backtesting with code and scripts

Automating the backtesting process using code and scripts can significantly speed up the testing and evaluation of trading strategies. Traders can use programming languages like Python to develop scripts that automatically execute trades based on predetermined criteria. This method allows for faster and more efficient analysis of large volumes of historical data.

Implementing algorithmic backtesting using predictive models

Algorithmic backtesting involves using predictive models and complex algorithms to simulate and evaluate trading strategies. These models analyze historical data and make predictions about future market movements. Traders can use algorithmic backtesting to test and refine their strategies based on predictive models’ outputs.

How can historical data be applied to improve trading strategies?

Identifying patterns and trends in historical price data

Historical price data allows traders to identify patterns and trends that can inform their trading strategies. By analyzing past market movements, traders can gain insights into recurring patterns and adjust their strategies accordingly.

Testing and optimizing trading strategies with historical data

Historical data provides a valuable testing ground for trading strategies. Traders can simulate trades using historical data and assess the performance of their strategies. By iterating and optimizing based on historical data, traders can enhance and fine-tune their trading approaches.

Using historical data to simulate and analyze portfolio performance

Historical data can also be used to simulate and analyze portfolio performance. Traders can assess the impact of different asset allocations, risk management strategies, and trading approaches on the overall performance of their portfolios. This helps traders make more informed decisions and manage their portfolios more effectively.

What are the challenges and considerations in using historical data for backtesting?

Addressing potential biases in historical data

Historical data may contain biases that can impact the accuracy of backtesting results. These biases can arise from factors such as survivorship bias and data selection bias. Traders should be aware of these biases and take steps to mitigate their impact on backtesting results.

The role of slippage and execution delays in backtesting

Backtesting often assumes perfect execution without considering slippage and execution delays. However, in live trading, these factors can significantly impact the performance of a strategy. Traders should account for slippage and execution delays when analyzing backtesting results and considering their strategies’ viability in real-time trading.

Selecting the right backtesting platform or software

Choosing the right backtesting platform or software is essential for accurate and reliable backtesting results. Traders should consider factors such as data quality, ease of use, customization options, and compatibility with their preferred trading strategies. Additionally, they should ensure that the platform or software supports the historical data they need for their backtesting purposes.

Q: What is backtesting and why is it important for trading strategies?

A: Backtesting is the process of testing a trading strategy using historical data to determine its accuracy and reliability. It allows investors to evaluate how a strategy would perform in various trading scenarios before risking real money. Backtesting is an essential step in algorithmic trading and can help traders improve their trading results.

Q: How can I access historical market data for backtesting?

A: There are various online sources where you can access historical market data. Some popular options include data providers like Bloomberg, Quandl, and Yahoo Finance. Additionally, many brokers and trading platforms offer historical data that you can use for backtesting purposes.

Q: What type of historical data should I use for backtesting?

A: The type of historical data you should use for backtesting depends on your trading strategy and the market you are trading. For example, if you are trading stocks, you may need daily data, while forex traders may require tick or intraday data. It is important to use data that matches the granularity and timeframe of your trading strategy.

Q: How can I backtest a trading strategy using Python?

A: Python is a popular programming language for backtesting trading strategies. There are several libraries like Pandas, NumPy, and Matplotlib that can be used to load and analyze historical data, implement trading strategies, and evaluate their performance. You can write code in Python to backtest your own strategies or use existing libraries and frameworks for automated trading.

Q: What is the role of predictive modeling in backtesting?

A: Predictive modeling plays a crucial role in backtesting by allowing traders to develop predictive models that can forecast future market movements. By incorporating predictive models into the backtesting process, traders can test strategies based on their ability to accurately predict market behavior.

Q: How can backtesting with historical data improve my trading results?

A: Backtesting with historical data allows you to assess the performance of your trading strategy and identify areas for improvement. By analyzing past trades and market conditions, you can tweak your strategy to maximize positive results and minimize losses. Backtesting helps you refine your trading approach and increase the reliability and yield of your trades.

Q: Can I use backtesting to test strategies for different financial markets?

A: Yes, backtesting can be used to test strategies for various trading markets, including stocks, forex, commodities, and more. The principles of backtesting remain the same regardless of the market you are trading. However, it is important to consider the specific characteristics and behaviors of each market when backtesting a strategy.

Q: Is historical data provided by online sources reliable for backtesting purposes?

A: The reliability of historical data provided by online sources can vary. It is essential to ensure that the data you use for backtesting is accurate and representative of the market conditions during the testing period. It is recommended to verify the data from multiple sources or use reliable data providers to minimize any potential discrepancies.

Q: What is the role of a backtesting method in evaluating trading strategies?

A: A backtesting method is a defined approach or set of rules that allows you to test and evaluate your trading strategies using historical data. It provides a systematic framework to assess the performance and profitability of your strategies. A well-designed backtesting method can help you identify strengths and weaknesses in your strategies and make informed decisions.

Q: What are some considerations for using tick or intraday data in backtesting?

A: When using tick or intraday data for backtesting, you need to consider the granularity and reliability of the data. Tick data provides the most detailed level of information, but it can also be noisy and require significant computational resources to process. Intraday data offers a balance between granularity and data size, making it suitable for many trading strategies. However, it is important to ensure that the intraday data accurately captures the price movements and market dynamics you are interested in.