Variance vs lemma

Prepare for quant interviews with focused practice in probability, mental math, sequences, and brainteasers. Variance brings quantitative training, performance comparisons, market reading, and career discovery into one app. Whether you're preparing for a trading or quant research interview, or sharpening your problem-solving skills, build a practice routine that fits your day. PRACTICE QUANTITATIVE SKILLS • Mental math and arithmetic • Probability and statistics • Expected value and conditional probability • Sequences and pattern recognition • Brainteasers and logic puzzles BUILD YOUR TRAINING ROUTINE Explore different practice modes and difficulty levels. Focus on specific topics, challenge your speed and accuracy, and review explanations in supported question modes. KNOW WHERE YOU STAND Track your performance and personal bests. Explore score distributions and percentile comparisons to understand how your results compare with other players. COMPETE AND STAY MOTIVATED Compare results on global leaderboards and work toward your next personal best. EXPLORE MARKETS AND CAREERS Read the market brief, browse finance firms, and discover quant internship and full-time opportunities through links to career resources and job boards. Built for students, aspiring traders, quant researchers, and anyone who enjoys quantitative problem-solving. Train with purpose. Prepare with Variance. Terms of Use: https://www.thequantprepapp.com/terms Privacy Policy: https://www.thequantprepapp.com/privacy

Train like a quant. Daily. Lemma is the focused, no-fluff prep app for quantitative interviews — built for students and grads targeting Jane Street, Citadel, Optiver, Two Sigma, and the rest of the trading-firm gauntlet. WHAT'S INSIDE WITH YOUR SUBSCRIPTION • Daily sprints — bite-sized timed sets of mental math, probability, combinatorics, expected value, and market-making problems • Per-category ELO — your skill is tracked across 10 disciplines, from Novice to Expert • Adaptive difficulty — problems chosen to keep you at the edge of your level, not above or below • Hints + step-through solutions — get unstuck without giving up • Streaks, XP, leagues — habit loops without the noise • Achievements — unlock as you grind • Leaderboard — see how you stack up WHO IT'S FOR • CS / math undergrads applying to trading firms • Recent grads prepping for technical interviews • Self-learners who want a daily quantitative-thinking habit • Anyone curious about how trading interviews actually feel WHY LEMMA We strip out the gamified clutter and keep what matters: hard problems, fast iteration, real numbers on your progress. The interface borrows more from a Bloomberg terminal than a typical mobile game — monospaced metrics, hairline borders, dark by default. Most prep books drown you in 800 pages. Most courses lock you in for months. Lemma is 10 minutes a day, sharpened every day. — Lemma offers an optional auto-renewable subscription for unlimited daily sprints and premium problem sets. Subscriptions auto-renew unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in your Apple ID settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://rogeru13.github.io/lemma-legal/privacy-policy/