How to Build Your First Portfolio
A simple, honest framework for getting started.
Start with what you know
Buffett calls it his 'circle of competence' — only invest in businesses you actually understand. You shop at Costco. You know the store is always packed and the membership is worth it. You use Amazon every week. You bank with JPMorgan. You already understand these businesses better than most Wall Street analysts. Start there. Familiarity is an edge.
Invest in what you know. Understanding the business is the first line of defense against a bad investment. — Warren Buffett
How many stocks to own
Buffett has said that for most investors, a concentrated portfolio of businesses you truly understand beats owning 50 stocks you barely know. 8-12 stocks is a solid range for most people — enough to diversify away bad luck, not so many that you can't keep track of what you own. Owning 50 stocks means you're basically running an expensive index fund with a lot of extra work. Own fewer. Know them better.
Diversifying across sectors
Different sectors perform differently at different times. Technology booms during innovation cycles. Energy does well when oil prices rise. Consumer staples hold steady during recessions. Holding a mix — some industrial, some financial, some consumer, some tech, some energy — means your whole portfolio doesn't move in the same direction at the same time. Use the blue screener to find B-rated or better stocks across sectors.
Position sizing: how much to put in each
No single stock should be more than 20-25% of your portfolio when you're starting out. Even if you're highly confident in a business, concentrating too much is how people lose life-changing amounts of money on a single bad outcome. Start smaller in each position and add to the ones that prove themselves over time. Your portfolio score in blue shows the weighted health of everything you own — watch it regularly.
What a starter portfolio could look like
A simple 8-stock starter across sectors: one or two consumer companies (COST, WMT), one or two industrials (CAT, DE), one or two financials (JPM, BRK-B), one healthcare (JNJ, LLY), one energy (XOM, CVX). Run each through blue before buying. Look for B or better across the board. This isn't a recommendation — it's a framework for how to think about building a balanced base.
Add a stock you already know well to your portfolio — a company you use or see every week. Watch how it affects your overall portfolio score.
Try it →Knowledge Check
1. What does Buffett mean by investing within your 'circle of competence'?
2. Why is owning 50+ stocks generally worse than owning 8-12 you understand well?
3. What is the recommended maximum position size for a single stock when building your first portfolio?
Next module
When to Buy, When to Wait →