Natalie Monko Lead Project Manager

    Stock Trading App Development: How to Build an App That Brings the Stock Market to the Public

    The appearance of easy-to-use mobile apps for trading and the pandemic that brought increased volatility to the market are all reasons behind the growing popularity of stock trading among individuals. In the second quarter of 2020, major American trading platforms such as Robinhood and TD Ameritrade, saw their trading volume doubling year over year. As a result, the growing number of traders and increasing competition lead many platforms to offer commission-free trading, earning instead from premium features, market makers and frequency trading firms. Still, many people don’t participate in the stock trades not because of commission fees, but rather because they lack financial literacy. 

    A mobile app that combines convenient stock trading with financial education and insights has a great potential of making a profitable business by attracting users who are still reluctant to invest in the stock market. Surf has created apps for banks and trading platforms and has extensive expertise in building apps for fintech. In the article, we’ll discuss how to create a stock trading platform, what features to include, as well as things to consider during development and how much it might cost.

    Popular stock trading apps

    Let’s have a look at some of the most popular trading apps and what they offer customers to their customers.


    Public is an app that positions itself as an ‘investing social platform’. The app lets users track the performance of other users’ portfolios and strives to build a community around the stock market. Public offers commission-free trading with no account minimum — a so-called “fractional investing” option allows customers to buy a ‘slice’ of a single share, making even expensive stocks affordable to anyone. Because of its simple interface and useful collections of stocks grouped by industries, the app is suitable for complete beginners — a person can invest in an area of the economy without doing extensive research on particular companies.

    public app


    One of the most popular trading apps in the world, Robinhood, has over 22 million users. During the 2020 pandemic, the app’s surging number of customers, as well as several lawsuits, made Robinhood one of the hottest topics in the news. The app lets users buy and sell stocks, options, exchange-traded funds (ETFs), and cryptocurrencies without commission. Also, the app pays interest on uninvested cash and helps with bills and paychecks management, acting as a personal finance app.

    Power E*TRADE 

    Catering to both casual investors and advanced traders, E*TRADE platform has $0 commissions on trades as well as rich educational resources. Power E*TRADE app provides access to hundreds of stocks, options, futures, and ETFs, and lets customers make both basic orders and use advanced trading strategies. The app provides customizable graphs, drawing tools for technical analysis and trading ladders. The educational resources of E*TRADE consist of webinars covering a full range of topics from such basic concepts as diversification to complex ones, for example, options trading.

    Power E*trade app


    eToro provides access to US stocks as well as popular cryptocurrencies, such as Bitcoin, Ethereum, XRP, and requires no account minimum. Trading with eToro is commission-free and every new user gets credited with virtual $100,000 to try out crypto trading before investing their own funds. One of the features that make eToro stand out among others is CopyTrader — it allows customers to choose a pro trader and automatically match their moves. The minimum amount to use CopyTrader is only $200 and a user can copy up to 100 traders at once.

    eToro mobile application

    Stock trading app features

    The best way to identify features for a stock trading app is to analyze how customers would be using the app.

    Authentication and security

    The app usage experience starts from the initial sign up or log in screen. Today, it has become common for people to open a brokerage account right in the app without visiting an office, so it is important to implement a convenient sign up procedure that requires only essential details, such as full name and social security number .

    After the first login, prompt the user to set up a PIN or Touch/Face ID that will block any unauthorized access to their financial data and operations. Also, consider turning on two-factor authentication via SMS or email codes for such operations as funds withdrawal. 

    Bank account linking

    To add funds and start trading, a user can simply transfer money from their banking account using brokerage account details, however, such operation may incur additional fees on the bank side. A more convenient option would be to allow a user to link their credit card with the help of such payment application programming interface (API) integrations as Braintree or Plaid, along with an option to top up the account via Apple Pay or GPay.

    Define the client’s goals

    The majority of trading apps try to access a new user’s risk profile and recommend stocks based on their willingness to risk. However, such an approach might lead to losing the client in the near future. Let’s say the client gets a ‘moderate risk’ profile and is offered to buy some popular stocks of large companies. Having no trading experience, the user buys the shares that soon fall in price. Seeing less money on their account, the user is disappointed and quits using the app.

    A better way to acquire a long-time customer would be to discover their personal finance goals instead of risk appetites. Based on the goals, the app can suggest what parts of the client’s funds should go into bulletproof retirement savings, stocks of well-to-do companies and even high-risk IPOs.

    Home screen

    The main screen that a user sees every time they login into the app, should provide a clear portfolio overview that is not only easy to read but also stress-free. If a trading app becomes strongly associated with ‘red figures’ a user might not want to open the app often. Provide customers with the ability to customize the home screen interface, so they can turn off charts, red arrows and other indicators if they want to.

    investing app

    Another important aspect is to allow users to set up separate investment portfolios relevant to their goals. For example, a user might have a ‘Retirement’ portfolio with low-risk assets and ’High risk investments’ with hot stocks. Portfolio categorization not only eases money management and performance tracking but also decreases stress levels: while the ‘High-risk’ portfolio might become entirely ‘red’ in times of increased volatility, the ‘Retirement’ category would stay ‘green’.

    Trading tools

    One of the most important screens of a trading app is the one where the user sees a chart of a particular instrument, its details (company’s information, dividend payouts, trading volume, and so on) and can buy or sell shares using market, limit, or other, more advanced types of orders.

    For a trading app, it is crucial to provide real-time charts that show accurate prices of instruments. Usually, this is done by connecting an external API and library to the app. For example, when Surf developed Twim crypto trading app, we chose TradingView library — one of the most popular platforms for market data visualization. By using gRPC (Remote Procedure Calls framework) we set up data transfer from the exchange server to TradingView, where it was then converted into charts and sent to the app through a WebView component. A combination of gRPC, HTTP/2, and protobufs allowed us to have quotes updating up to 20 times per second.

    crypto trading app

    News feed

    To help customers make informed decisions, include a news feed that has both short reports on current events and more in-depth analytical pieces. While many trading apps provide access to main American, European and Asian markets, it is important to cover events on each of them, but, since not every app user trades on every market available, a filter option would help make news more relevant for them.


    Novice investors do not have deep knowledge of financial instruments and particular securities. While a completely ready-made portfolio or trading strategy can suit some users, in its investment app concept Surf suggests an approach that mixes both elements of trust management and independent decisions.

    invests app

    A trading app robo-advisor can suggest particular instruments according to the user’s profile and goals. Then the user makes necessary adjustments and buys chosen securities. While robo-advisors are not the best option for complex and high-risk strategies, they can completely satisfy entry-level investors who do not want to follow daily financial news or perform technical analysis. As well as building an initial portfolio, robo-advisors can help with regular portfolio rebalancing and optimization.

    Auto trading options

    Today it is common for mobile trading apps to offer some degree of automatization for greater convenience. For example, if a user invests a part of his salary once a month, the app can offer to buy stocks and other instruments according to their preferences and asset allocation strategy. With the auto purchasing feature, the client can submit numerous purchase orders every month with just one confirmation click.

    Another way to automate the trading process is copy trading. The feature lets the user pick a top professional trader and automatically copy every deal they do (of course, the amount of purchased or sold shares is adjusted to the user’s portfolio). Copy trading is a hands-off approach that requires minimal involvement from a user and allows stock market newcomers to trade beyond their expertise. The main downside lies in taking on the risks of another person with your own money. 

    Performance analysis

    Clean and understandable portfolio analytics not only helps a user to see how much money they made or lost, but also reinforces trust in the trading app that offers transparency. The app should include performance analytics in the form of charts and diagrams with options to analyze dynamics during a particular time frame (week, month, year) and compare different instruments.

    Easy access to documents

    Investors often require details of their trades for annual tax reports and other financial documents. A trading app should include a comprehensive section where a user can easily download all required documents. 

    For example, while working on a corporate banking app for Rosbank (part of Société Générale group), Surf developed a “repeat” feature for the Document section that allows a user to generate financial reports from existing templates in just three clicks. Also, all documents in the section can be filtered by date, amount, status and other parameters. 

    Things to consider when developing trading app

    Mobile-first approach

    A process of trading application development consists of four main stages:

    • Discovery. The team analyzes the market, competitors and defines your perfect user.
    • Design. Creation of screen mock-ups and app prototype, gathering feedback from people.
    • Development. Writing the app’s code itself and building MVP (minimum viable product).
    • Test & improvement. The team tests and improves the app, adds new features and finally releases the app publicly. 

    Because today smartphones have become the main tool for trading, it is important to thoroughly plan the app’s appearance and how it would be used during the design stage. Even if you already have a trading platform for web or desktop, investing in a dedicated UX/UI design for a mobile app would be beneficial in the long run and attract more customers. An attempt to simply adapt the web-based design, where every screen has many features available at the same time, might not work on smaller devices — mobile apps tend to have simplified screens with an ability to quickly switch between them. How exactly these screens should look is decided by extensive study of the app’s user flow and the results of the app’s prototype testing sessions.

    One of the main trends in trading and investing is highly personalized investment advice offered by banks and brokerage firms. While this can be achieved by combining both digital robo-advisors powered by AI and the expertise of human investment advisors, the alternative to this approach, which potentially bears fewer costs and risks for the bank, is social trading.

    One of the prominent examples of an app with social trading focus is Public. Users of the app can set up publicly visible profiles and share their trades, portfolios and ideas on the current market situation, while other users can follow them and mimic their trades. Also, Public app has a social feed similar to that of social networks. What appears in a person’s feed depends on whom they follow and what instruments they are interested in. Together with private and group messaging these features help Public create a social community around finances and supply users with trading ideas via crowdsourcing.

    Educational resources

    Since users are often reluctant (and rightfully so) to use trading instruments they are unfamiliar with, an education platform integrated within the trading app would improve users’ financial literacy as well as stimulate them to do more trades. The lessons can be made in text or video formats and should cover every trading aspect, from basic terms to advanced strategies. Putting short explanations and links to relevant lessons on the trading screen would help spread knowledge more easily. Investment into improving financial literacy is a smart investment — people with better knowledge would make better trades and be happier with the trading app.


    As well as other fintech industry products, trading apps are highly-scrutinized by governments all over the world. As more and more people choose the services of fintech startups, these companies process more money, leading to even bigger attention from regulators.

    For example, for a trading platform to legally operate in the US, it should comply with such regulations as Know Your Customer (KYC) — a mandatory process of a client’s identity verification; Anti-money laundering (AML) — requirements to actively monitor and report suspicious activities; Dodd-Frank Act — a set of laws regulating high-risk financial products; Gramm-Leach-Bliley Act — requirements to disclose information-sharing practices to customers and protect their private data, and others. A US-based broker would need to register with the Security Exchange Commission (SEC), become a member of Financial Industry Regulatory Authority (FINRA) and Securities Investor Protection Corporation (SIPC) as well as other state-specific regulatory organizations.

    To decrease regulatory challenges, many fintech companies decide to partner with an established bank that has already obtained the necessary licenses and become providers of technical solutions for them. Another way to speed up the licensing process is to use the services of regtech (regulatory technology) companies that help startups with compliance and regulatory monitoring. Read more on how to manage compliance risks in our “Fintech Compliance Regulations” article.

    Trading app development cost

    The price of developing a stock trading app depends greatly on its set of features, along with other factors, such as supported platforms and used technologies. In general, it would take 5 – 9 months for a skilled team of developers to build a trading app, which amounts to 2500 – 3000 development hours. With an hourly rate of $40, this equals $100,000 – 120,000. However, the figure can be lower or higher, if, for example, you decide to develop an app with a sole focus on crypto trading or enrich the trading app with personal finance and budgeting options.

    While mobile app development doesn’t come cheap, there are many ways to drive down the costs. For example, using a cross-platform framework to build both iOS and Android apps from one set of code rather than developing two separate apps can potentially save up to 40% of the budget. At Surf, we use Flutter for cross-platform projects, including fintech apps. 

    Another cost-saving option is to seek developers offshore, where hourly rates of high-quality specialists can be twice as low compared to their US-based colleagues. For example, the average salary of a developer from Russia or Ukraine is $35–50 per hour, while it is $90–110 in the US and Western Europe.

    Using off-the-shelf SDKs (software development kits) and other ready-made solutions, such as APIs, saves plenty of resources and makes the development process faster and cheaper compared to building all features from scratch. For example, to get real-time data for orders and positions such APIs as Tradier or Alpaca can be used, while Zirra products help with scoring & portfolio construction. A thorough study of the available tools would help pick the most suitable and affordable solution for every task, from linking credit cards to support chat.

    Also, check our article where we discuss factors that affect app development price in more detail.

    To sum things up

    As stock and crypto markets attract more traders, the demand for mobile apps that allow trading from any place in the world grows. Despite the 2020 surge in the number of brokerage accounts, there are still many people who don’t trade yet due to the seeming complexity of trading and lack of financial literacy. A trading app that offers a simple and clean interface, educational resources and social features that connect to more experienced traders, has a great potential to attract a large user base and become a profitable business. 
    We at Surf have over a decade of experience developing native and cross-platform mobile apps and recently have done multiple fintech projects, such as apps for banks and trading platforms. If you want to develop a trading app, fill in the form, and we’ll contact you shortly to discuss your project in detail.