Top Stock Market API Providers – A Guide for Investors

A review of the top-notch stock APIs in 2020-2021 for tech-savvy investors, asset managers, and software developers.

Top Market Data API Providers (2020-2021)

Index of data providers covered in this article:

  1. Alpha Vantage
  2. Bloomberg API Library
  3. Polygon
  4. QuoteMedia
  5. IEX Cloud
  6. Google Finance via Google Sheets

Financial market data is the critical component of any trading strategy or financial technology (fintech) applications. In the cloud-first, mobile-first era, a number of API providers have established themselves in the $30-billion financial market data industry. This article surveys some of the top incumbents in the industry as we enter a brand new decade in 2020.

1. Alpha Vantage

Alpha Vantage is a free stock API provider backed by the Y Combinator and incubated at the Harvard Innovation Labs (iLab). Since it’s founding in 2017, Alpha Vantage has garnered a loyal following from the global open-source community. On GitHub alone, there are about 500 open-source libraries that are built on top of its diverse API portfolio, covering all major programming languages such as Python, Java, and Javascript. Among some of the other financial API providers, Alpha Vantage has a strong suite of product offerings for time series analysis, which makes it a natural choice for investment professionals to backtest their trading strategies with historical time series data. Moreover, with its broad spectrum of programming language support, Alpha Vantage is arguably the most developer-friendly API provider for a variety of form factors such as web (Javascript, Python), Android (Java), and iOS (Objective C, Swift).

Selected product offerings:

  • Historical data for stocks, ETF, and mutual funds
  • Realtime and historical data for forex and cryptocurrencies
  • Derived financial data such as 50+ technical indicators
  • Spreadsheets via Google Sheet and Excel Office 365


2. Bloomberg API

I know what you may be thinking:

Wait? Bloomberg also offers APIs? I’ve only seen those Bloomberg machines in my school library!

The flagship product of Bloomberg is indeed the on-premise Bloomberg Terminals that have been trusted by banks and hedge funds for several decades. However, Bloomberg hasn’t missed the digital transformation in the financial data industry. It does offer a suite of APIs for programmatic access to the stock market – with a condition: you still need to operate within the Bloomberg ecosystem. Specifically, these APIs are designated by Bloomberg’s Enterprise Products team for use by Bloomberg customers.

Selected product offerings: the full range of functionality supported by the classic Bloomberg Terminal, such as stock, funds, index, options, futures data as well as other alternative datasets. SDKs are available in Windows, MacOS, Linux across major programming languages such as C/C++ and Python.



Polygon API
When it comes to stock exchanges in the United States, you may think of NYSE and NASDAQ. In reality, there are more than 10 stock exchanges in the US, with several more to come in 2020 or 2021. For investors and software developers, this can lead to confusion. Let’s say you want to query the closing price of Microsoft (MSFT) through your favorite stock API. It’s sometimes hard to know whether the data feed is from a particular exchange or a market-wide aggregation across all trading volumes from all the exchanges. There is where Polygon comes in. This Atlanta, Georgia based company gives you full flexibility to query any one or all of US exchanges based on your business and data needs. Polygon’s servers often co-locate with the exchange servers, which means the live stock data you receive from Polygon will be ultra low-latency with nanosecond precision. With such robust infrastructure, it’s no wonder that Polygon counts Google and Robinhood as its enterprise customers.

Selected product offerings:

  • Ultra-low-latency realtime stock data from US exchanges
  • Realtime forex and crptyocurrency data


4. QuoteMedia

QuoteMedia provides enterprise-level access to a wide range of financial markets in North America, Europe, Asia Pacific, and other major global trading venues. It does not openly publish its pricing tiers, but its sales and support representatives are there to tailor the data offering to the specific business requirements of the clients. In addition to primary stock data feeds, QuoteMedia also offers secondary/derived market data such as Option Chains.

Current events such as the GME price movement have shown how market sentiments can be a powerful force in driving short-term asset prices. Complementary to its core quantitative equity market data suite is QuotaMedia’s News API, which “aggregates news, press releases and online content (portals, web content, finance blogs, etc.) from over 300 sources” and can potentially add valuable market signals to augment trading strategy development. Current events such as the GME price movement have shown how market sentiments can be a powerful force in driving short-term asset prices.

Selected product offerings:

  • Realtime and historical data market data
  • Analyst ratings and earnings
  • News and headlines
  • Option and option chains


5. IEX Cloud

What happens if you move the Bloomberg machines to the cloud? You get IEX Cloud! The company started as an independent stock exchange called the Investors Exchange and later expanded into the market data domain. This unique path of evolution means that IEX Cloud offers both first-party exchange data from IEX and third-party financial market data.

Selected product offerings:

  • First-party realtime and historical market data from IEX
  • A diverse portfolio of third-party data such as fundamental data, market-aggregated stock data, forex, crypto, and alternative data (e.g., news).


6. Google API (via Google Sheets)

The official Yahoo Finance API and Google Finance API have been deprecated. However, Google still allows users to access financial market data via Google Sheets. This can be an attractive option if you would like to access free, high-quality market data via spreadsheets. On the flip side, you will probably need to look for other options if your end goal is to integrate with a stock API that is NOT bind to Google Sheets.

Selected product offerings: a diverse set of market data via the GOOGLEFINANCE function in Google Sheets.





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Student comments on Top Stock Market API Providers – A Guide for Investors

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