BetaDay is an iOS app I built to get better at making decisions under uncertainty. Every day, it presents a stock and asks: will it go up or down? You make your call, assign a confidence level, and the next day you find out how you did.
Features
- Daily Predictions: One stock prediction per day with confidence levels
- Four-Quadrant Retrospective: See your results organized by confident-right, confident-wrong, uncertain-right, uncertain-wrong
- Decision Quality Tracking: Track calibration over time, not just whether you were right
- Historical Review: Browse past predictions and see how your judgment evolves
- Market Data: Real stock market data so the randomness is genuine
How It Works
The point isn’t to become a stock picker. The point is to practice the meta-skill of knowing how much you know. The four-quadrant view is the key insight: being confidently wrong is very different from being uncertainly wrong, and the app helps you see which quadrant you tend to land in.
Over time, well-calibrated thinkers should be right about 50% of the time when they say they’re uncertain, and much more than 50% when they say they’re confident. BetaDay tracks whether that’s actually true for you.