Keep an eye out of this platforms that offers bitcoin exchange source code especially if you do not have a deep background or extensive technical knowledge on this matter since building a cryptocurrency exchange is not as simple as we might think.
Building an exchange should be done deliberately and having the control of people's money, and being the intermediary of their trades needs a well-educated technical team behind a complex project. Secondly, it is a no-brainer that opening an exchange also needs to consider the legal implications as it will serve as the protection for people who uses the platform especially if the source code you will be using is not originally created by you.
In fact, people with no programming background should not use an open source code of a bitcoin exchange because of the possibility that it might have a backdoor written on it which can cause a catastrophic failure of funds being lost.
At the same time I would like to state that there is a very big factor
Competition, there are many exchanges out there in the market and I do think which makes it even harder for a person to invest in a particular exchange. With some of the major exchanges going down in the market over the years , I do think you can first buy a share in the exchange you are interested in and then see it's growth over the year , if you do believe that it does have a lot of potential then only you should go forth and make the investment , it is never going to be a safe bet but with an exchange that you would have worked with and looked after from the sidelines, you might know the pros and cons and at the same time you can plan it in a way that you can make use of its full potential.
Your exchange might :
Enable smart contracts
Be available offline which would even make it beneficial for traders
Might require no KYC and private information
Can even work with cash-btc
There are so many things that you can do , you can ever start a poll and ask people what would they require from an amazing exchange platform and then filter out things and see for yourself that what might be beneficial for both the users and the company.
Its a lot of hardwork.