Reliable Financial Data for Data Science Projects

Written by Paramesh Palanisamy

March 14, 2022

Press Release

We’ve all heard the claim that “data is the new oil”. But just like oil, data needs to be refined before it can be of any real use. To put it more specifically, capturing data and using it effectively are two very different things.

The financial industry, in particular, is one industry where having access to quality and updated data is crucial given the highly dynamic nature of this industry. Obtaining accurate, reliable, historical and real-time financial market data is surprisingly difficult. Getting that data into a usable format is even more so.

Introducing Polygon

The project I was working on required Historical and real-time Finance market data over a period of time. After googling and asking around for various platforms, I ended up with Polygon. I found the service competitively priced, stable with excellent documentation. As a result of my positive experience with the platform, I decided to share my experience via this post for anyone who might be in the same boat.

Polygon offers Real-Time and Historical Financial Market Data of Stocks, Forex and Crypto! These data accessible through RESTful and WebSocket APIs. Their API is powering best-in-class financial and technology customers including Google, Revolut and the most popular Retail Broker Robinhood.

The Data

Polygon provides following data products: Stocks, Options, Forex Currencies & Cryptocurrency
Below are the features of each data services:

Feature Stocks
All US Exchanges + Dark Pools
Crypto + Forex
All US Options
Unlimited API Calls
(REST API + WebSocket)
Yes Yes Yes
Real-time Data Yes Yes Yes
Historical Data 20+ Years 10+ Years 5+ Years
Reference Data Yes Yes Yes
Fundamental Data Yes Yes Yes
Corporate Actions Yes Yes

Performance is located in the datacenters with NYSE, NASDAQ, BATS, IEX and the other top exchanges. They connect directly to the exchanges to bring you institutional level data, that has previously been out of reach for most end users, fast. Responses can be as quick as 2 milliseconds. You can see why businesses with serious customer needs are relying on polygon’s API.

Accuracy provides 999,999 units of accuracy more than competitors. Their data APIs provides all the timestamps you need to know where and when a occurred with nanosecond time accuracy.

Ease of Use has several Open-Source projects that you can use to easily interact with our financial data APIs. They also provide client libraries for popular languages:






The API is also well documented and intuitive. It took me only a few hours to get up and running. RESTful APIs require you to send a request and wait for a response. WebSockets are an open connection streaming data from our servers to your client without any delays. APIs documentation sources are tabulated below:

Product RESTful WebSocket


In the end I added Polygon’s data as a “source” for all of my finance data analysis because of their easy-to-use RESTful APIs and WebSockets. So far, I have only been able to utilize the Stocks data but will likely play around with the crypto and forex data as well in future. Happy data sciencing!