Listen now on YouTube, Spotify, and Apple.
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Kevin Xu, perhaps better known by his Reddit moniker - Sir Jack, built an $8M fortune trading stocks on Reddit’s WallStreetBets before leaving his day job at YouTube to build AfterHour, a stock market super app. It raised $4.5M in it’s seed round last year.
Some takeaways:
🎯 Community Building 101:
Go where your audience already is - Kevin saw 10x better results from engaging on Reddit vs traditional media like Fox Business or documentaries
Authenticity trumps strategy - Kevin's SirJack persona succeeded because it wasn't originally meant to be anything, just genuine trading updates
Communities need a clear reason to exist beyond just "having a community" - for AfterHour, it's helping people make money together
💡 Growth in 2025:
Product differentiation is crucial - Kevin identified a key gap in finance platforms around trust and verification of trades
Three viable paths to growth: novelty (viral AI features), authenticity (genuine creator connections), or enabling creators to monetize
Mobile-first matters - Kevin intentionally built AfterHour as a "bathroom app" to capture daily habits and leverage push notifications
🎨 Design Philosophy:
Ruthlessly eliminate complexity - AfterHour limits screens to 2 main buttons max
Only show what matters most - resist the urge to display every possible metric just because you can
Design for the average user, not power users - most people don't need every feature from Yahoo Finance
🚀 Platform Building:
Communities need to evolve into "communities of communities" to achieve long-term sustainability
Focus on unique value-add vs replicating existing tools - AfterHour emphasizes social features over duplicating stock data available elsewhere
Trust and verification are crucial - Kevin built features to verify trades because screenshots alone weren't enough
🔑 Key Leadership Insight:
Different phases need different skills - early stage (0-0.1) requires hands-on community building and DMing users individually, while scaling requires shifting focus to product and broader marketing initiatives
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Where to find Kevin Xu:
Website: https://afterhour.com/
LinkedIn: https://www.linkedin.com/in/imkevinxu/
X: https://x.com/imkevinxu
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In this episode, we cover:
00:00 From Reddit Fame to Startup Success
01:29 The Journey of Entrepreneurship
04:20 The Rise of Wall Street Bets
06:23 Building a Community in Finance
09:34 The Transition from Anonymity to Identity
12:28 Creating a Financial Super App
15:14 Navigating Fame and Community Engagement
17:37 The Role of Authenticity in Community Building
20:42 Balancing Personal Brand and Business Goals
23:11 The Impact of Media on Business Growth
32:02 Building Community on Reddit
35:42 Onboarding and User Experience
37:20 Marketing Strategies on Reddit
39:34 The Role of Community in Marketing
41:24 Control Over Algorithms and Content
42:56 Algorithm Development for Diverse Users
43:45 Community Building Strategies
47:00 Sustaining Community Longevity
47:58 Mobile-Only Strategy
50:09 Design Principles for User Engagement
54:42 Leveraging AI in Development
57:38 Essentials for Building a Community
01:01:38 The Future of AfterHour and Community Dynamics
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Obligatory disclaimer: I've worked at YouTube and Google for about a decade in various marketing teams. Nothing I say in my personal spaces is necessarily endorsed by them.
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