5 May 2026

Kako je frustracija u trejdanju postala biznis ideja

I’ve been trading for several years and, like most people who are just starting out, I didn’t make progress the way I wanted for a long time. My name is Roko Režić, I’m a student at ZSEM and co-founder of Trader, a mobile app for traders that I’m building together with my friend Tin. Over time, we realized the problem wasn’t in the strategies we were using, but in the fact that, like most traders, we avoided backtesting. It’s the process of practicing strategies on real historical data and is key to developing discipline and consistency. The problem is that almost no one does it because it’s slow, repetitive, and it’s hard to track real progress.

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That insight led to the creation of Trader. It’s an app where users go through real historical charts and make decisions – buy, sell, or skip – while the app tracks every move, measures progress, and uses gamification elements like leaderboards, trophies, and challenges to keep users motivated. The idea was simple: turn backtesting from something you procrastinate on into something you actually want to do every day.
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Tino and I have known each other since kindergarten, and before Trader we had already worked on several projects together, which helped us build a strong team dynamic. We both actively trade, and that’s probably our biggest advantage – we’re not building a product for unknown users, but for people who think like we do. We understand how young people use apps, what keeps them engaged and what turns them away, and we’ve tried to incorporate that into every part of Trader.

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Studying at ZSEM gave me the opportunity to further broaden my perspective through various international experiences. I went on exchange to Madrid, participated in a winter school in Turkey, a summer school in New York where I earned the Bloomberg Market Concepts certificate, and a program in Lithuania. These experiences helped me better understand markets, but also think more broadly about how to build a product for a global environment.

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We applied to the ABC Venture Challenge and won 2nd place as the only team from Croatia among the awarded participants. When you work on something for a long time alongside your studies, without external funding, that kind of external validation really means a lot. It gave us additional confidence that the problem we’re solving has value beyond our immediate environment, as well as the motivation to keep going. As a result, we will soon be traveling to Silicon Valley for the ABC Silicon Valley program in San Jose. This is a great opportunity for us to work with mentors, meet people who have built the industries we are just entering, and experience it all firsthand.

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Trader will soon be launching on iOS and Android, and that’s what we’re most excited about right now – entering the global market, getting our first real users, and everything that comes once the product truly comes to life in the real world. If you trade or know someone who does, visit traderbacktesting.com.