Best 5 Stock Market APIs in 2020 – A Guide for Investors

An analysis of the best stock APIs in 2020 for tech-savvy investors, asset managers, and software developers.

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 the top incumbents in the industry as we enter a brand new decade in 2020.

Top Market Data API Providers in 2020

  1. Alpha Vantage
  3. Bloomberg APIs
  4. IEX Cloud
  5. Google Finance via Google Sheets

1. Alpha Vantage

Alpha Vantage is a stock API and market data company 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. Regarded as a well established stock API provider, 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).

Product offering:

  • 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 O365



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 GA based company gives you full flexibility to query any one or set 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-level precision. With such robust infrastructure, it’s no wonder that Polygon counts Google and Robinhood as its enterprise customers.

Product offering:

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


3. 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.

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.


4. 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.

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).


5. 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.

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





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1 thought on “Best 5 Stock Market APIs in 2020 – A Guide for Investors

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