This question-asking by everyone who is looking for reliable, affordable, and easy to use Stock Market Rest API nowadays. Today I’m going to explain what makes a stock market API good and bad then I will let you decide what makes a stock API good or bad?

First of all, let's clarify the features of a stock market API;

• Market Coverage
• Response Latency
• JSON End Points
• Included metrics
• API calls
• Historical Data
• Documentation
• Price

API – Application programming interface, it will create infinite numbers of advantage whoever like to build great applications.

FINAGE

STOCK MARKET API – MARKET COVERAGE

• When are you trying to choose the best market API for stocks you need to clarify which stock exchange which stocks you need?
• The most popular stock exchanges in the world are; New York Stock Exchange, Nasdaq, Japan Exchange Group, London Stock Exchange, Shanghai Stock Exchange, Hong Kong Stock Exchange, Euronext and etc.

The most popular stock exchanges for trading/investing and developers are NYSE and Nasdaq in that case a good stock market API has to cover 100% of US stocks more stock exchange will make better opportunities and move coverage.

A good Stock Market API also has to cover Indices, Mutual Funds, Futures, and Options too. These are all available when you get a great stock market API.

STOCK MARKET API – RESPONSE LATENCY

Latency is really critical measure for any API but especially when it comes to Stock API it is way more than important it has to be reliable latency.

First, to full you need to learn data provider server locations then you need to choose the closest server to your server. You can check server pings with the tool given below:

This is the tool you can see milliseconds between cities in the World:
https://wondernetwork.com/pings

This is also a tool you can calculate exact ping ms latency from your server to the data provider server:
https://www.ipaddressguide.com/ping

For example, you find the latency is: 100ms

Then you need to make a request with the API and using the Google Chrome Inspect option you can see what is the interior response time.

HERE IS AN EXAMPLE OF RESPONSE THAT MEANS 120-100 MS = 20MS INTERIOR LATENCY.

UNDER ~50MS DELAY WOULD BE GOOD, UNDER ~20 MS IS THE GREAT FOR API FOR USING PROFESSIONAL USAGE.

STOCK MARKET API – ENDPOINT

A good Stock API has to return an understandable and readable JSON response. It will improve software coding quality and help developer implementation during the development phase. 

This is a good example for APPLE stock and Currencies response by API:

The short attributes have the name clearly understandable by the developer. It will provide quick coding and feedback.

STOCK MARKET API – INCLUDED METRICS

There is also a feature all good APIs can able to call. When you decide to choose and Stock Market API you have to identify the specific metrics you need to use in your platform like;

Open, Close, High, Low, Volume, Timestamp, Ask, Bid, Last Price, etc.

This is critical for deciding which API will work for you then you have to learn which metrics you need to use.

When Stock APIs designing these are implemented by the first stage after development finish and connected to a source of financial data adding a new metrics would be the hard job you should select the APı with considering that fact. They cant add new metrics just for you easily it has to be included at the first stage.

STOCK MARKET API – API CALLS

Another decision maker option for APIs is the limitation of usage. Lots of data vendors using API/calls, messages, requests, and other names to limit API Responses to spreading different packages, it is a commercial decision.

When you select 100.000/ API calls per month and need more upgrading wouldn’t be cost-efficient at the first stage you need to calculate how many calls will you need per month.

A good API has a scalable one whenever you need more it will automatically upgrade API/calls with an affordable price to keep you in the connection.

The best way scenario finding an unlimited request package they would be the best price/performance services.

STOCK MARKET API – HISTORICAL DATA

This is a game-changer option for all Stock Market APIs. There are historical data available up to +50 years by seconds/minutes/hours/day/month and year etc. 

There are two questions you need to ask yourself: How many years do I need? How often timeframes would be enough for my needs.

The most popular option is +15 Years of Historical Data from Seconds aggregated to Years. You can also able to download this data without limitation to use in local software and in an excel sheet. A good stock market API has to provide historical data in the way we mention above. 

Historical data are the most affordable data in the market all the data vendors providing this feature inside of the Stock Market API packages. You should consider subscribing to this kind of service

STOCK MARKET API – DOCUMENTATION

Documentation is the key to a successful and great API. It has to be simple and at the same time detail that is a thin line. Developers should understand what are they reading in seconds. They should be samples of usage with the code samples. The especially first connection, calling, and getting a response to sum up getting started parts are so important. 

This is a good example of documentation – minimalist and understandable:

Documentation also has to provide major programming language examples and support.

STOCK MARKET API – PRICING 

When we came the pricing is an also important subject. You always have to think about the price/performance ratio. Cheaper options always have problems with support, poor latency, lack of enough documentation and poor coding APIs can create lots of troubles during the development phase.

You have to act smart when you select your package lots of data vendor provides yearly discounts when a minimum one-year commitment. You also can take trials before you buy the services. 

Try first to feel the differences and choose your best options to build something amazing. You cannot make deductions from a good API. It will give you time, quality, reliable service. 

CONCLUSION – THIS IS YOUR DECISION

When we came up to an end, this is your choice you have to be smart when you choosing a great API for your needs. There are also some tips and recommendations for you; check the live support and technical support that will earn you more flexibility and information during your development process.

We are suggesting to you Finage – is a new generation financial data provider company focusing on the user's satisfaction. This user-driven approach powered by great Stock APIs, Real-Time WebSocket connection, and Live Technical Support on 7/24. 

You can visit Finage for affordable and reliable financial data services

Regards.