Development of the web applications is one of the most wanted programing activities today. Many young programmers have chosen this industry because they wanted to make web pages. Detailed description of MERN stack parts can be found in theoretical part of the thesis. Suck as use of MongoDB database to store data, NodeJs and ExpressJs framework for developing backend and React for frontend of the website. It was noticed that there are certain advantages in using MERN stack over ASP.Net Core. Bigger community of programmers developing packages and easier use for some applications are some of the main advantages. But there are also advantages in using Asp.Net Core over MERN stack such as using MVC architecture and IntelliSense which offers easier writing of code. Several safety mechanisms such as hashing and jsonwebtokens are described and used in this website. The process of making MERN stack website for buying and selling stocks is described in second part of the thesis. User can register or login to an existing account. During the register or login procedure if the user made a mistake he will receive an error message. Users can also buy and sell most wanted stocks. During buying or selling user can change the quantity of stocks and buy or sell multiple stocks at once. In the profile they can also change name, email and password. During the making of the website many things were noticed that havent been known before making this project such as using CanvasJs for making graphs of stock prices and using routing to change sites and transfer data across sites. Main thing that was noticed was extreme flexibility and effectiveness while using this technology for making web pages.