Buying Logic
Only buy when you think it’s cheap—regardless of what the market (others) thinks
📌 Concept Explanation
Buying logic = Only buy when you believe it’s cheap (price below intrinsic value). The judgment standard is company value, unrelated to stock price history or market sentiment.
You go to the vegetable market to buy tomatoes—you have a price in mind—you won’t buy if it’s over 3 yuan per jin. Whether yesterday it was 2 yuan or 5 yuan, whether people around you are snatching them up or not, you only care: is today’s price worth it? Duan Yongping’s stock-buying logic is exactly the same—if you think it’s cheap, you buy; it has nothing to do with how others see it.
💡 Core Understanding
1. The only standard for buying is that you personally think it’s cheap—independent of the market.
Each stock buyer “prices” the stock themselves—it’s not others saying it’s cheap, not that it has fallen a lot, but your own judgment of discounted future cash flow tells you this price is below intrinsic value. Only when you can truly ignore the market can you say your understanding of value investing is in place.
2. Buying is unrelated to stock price history—the only judgment standard is: company value.
What price this stock once reached should not become a reason to buy. Similarly, selling is also unrelated to your purchase cost—selling logic and buying logic are one and the same; both only look at the company itself.
3. Buying stocks means buying the company—you must think as if buying the entire company.
Before buying, ask yourself: If I had enough money, would I be willing to buy the entire company? This question helps you return to the essence of buying stocks is buying companies, rather than looking at a piece of paper that can go up or down.
4. Stocks you don’t plan to hold for 10 years—definitely don’t plan to hold for 10 days.
Before buying, think clearly about your holding logic. If your holding logic is just “it will rise short-term,” then you’re speculating, not investing. Long-termism is the natural extension of buying logic.
💬 Original Quotes
“Stocks are ‘priced’ by each buyer themselves—you can only buy when you yourself think it’s cheap; actually, it has nothing to do with the market (others).” (Source: Investment Logic · Chapter 5 Section 5, 2012-04-14)
“It’s the same when buying. There can be many reasons to buy, but what price this stock once reached had better not be your reason. My judgment standard is value.” (Source: Investment Logic · Chapter 5 Section 5, 2010-03-27)
“Stocks you don’t plan to hold for 10 years definitely don’t plan to hold for 10 days, otherwise you’re just ‘speculating’.” (Source: Investment Logic · Chapter 5 Section 5, 2011-12-13)
“Buying stocks has nothing to do with what this stock cost in the past, just like selling stocks has nothing to do with purchase cost. If you don’t understand this point, you’re just a trader.” (Source: Investment Logic · Chapter 5 Section 5, 2012-01-28)
🛠 How to Practice
Before buying, ask yourself two questions:
- Do I truly understand this company? The prerequisite for buying is being within your circle of competence. Companies you cannot understand, no matter how cheap, cannot be bought—“If you haven’t understood it, what kind of move are you making?”
- Do I personally think it’s cheap? Not others saying it’s cheap, not that it has fallen a lot, but your own judgment of discounted future cash flow telling you this price is below intrinsic value. If you need a calculator to figure out even a little bit of cheapness, then it’s not cheap enough (rough estimate).
After buying, there’s only one thing to check:
Does the logic at the time of buying still hold? Have there been fundamental changes to the company’s business model and corporate culture? If not, price fluctuations have nothing to do with you.
⚠️ Common Misconceptions
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❌ “The stock price has fallen a lot, so it’s a buying opportunity” — The buying standard is “you personally think it’s cheap,” not “how much it has fallen.” A stock that has fallen a lot but is still overvalued is not worth buying; the key is your judgment of company value, not the magnitude of price changes.
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❌ “Wait until market sentiment improves and someone is willing to take over before buying” — “The most important thing about investing is actually being able to ignore the market.” Waiting for market sentiment to improve before buying often means it’s no longer cheap by then. (Source: Duan Yongping Investment Q&A (Investment Logic), 2012-02-14)
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❌ “Before buying, research many companies—cast a wide net” — “I understand very few businesses.” In 10 years, he only made heavy investments in 5 companies. The prerequisite for buying is truly understanding, not broad exploration.
🔗 Related Nodes
Upstream concepts (prerequisites for understanding this concept): Buying Stocks is Buying Companies · Discounted Future Cash Flow · Circle of Competence · Margin of Safety
Downstream concepts (conclusions derived from this): Selling Logic · Concentrated Investing · Ordinary Mind
Related Company Cases NetEase (bought at 1 yuan, held for 8-9 years) · Apple
Related People Duan Yongping · Buffett
买入逻辑
只有自己觉得便宜才能买，和市场（别人）无关
📌 概念解析
买入逻辑 = 只在自己认为便宜（价格低于内在价值）时买入，判断标准是公司价值，与股价历史、市场情绪无关。
你去菜市场买西红柿，你心里有个价——超过3块钱一斤就不买。不管昨天是2块还是5块，不管旁边的人抢不抢，你只看今天这个价格值不值。段永平买股票就是这个逻辑——自己觉得便宜就买，和别人怎么看没关系。
💡 核心理解
1. 买入的唯一标准是自己觉得便宜，与市场无关。
股票是由每个买家自己”定价”的——不是别人说便宜，不是跌了很多，而是你自己对未来现金流折现的判断告诉你这个价格低于内在价值。能真正做到忽略市场，对价值投资的理解才算到位。
2. 买入和股价历史无关，判断标准只有一个：公司价值。
这只股票曾经到过什么价位，不应该成为买入的理由。同样，卖出也和买入成本无关——卖出逻辑和买入逻辑是一体的，都只看公司本身。
3. 买股票就是买公司，要像买整个公司一样思考。
买入前要问自己：如果有足够多的钱，我愿意把整个公司买下来吗？这个问题能帮你回到买股票就是买公司的本质，而不是在看一张可以涨跌的纸。
4. 不打算拿10年的股票，一定别去打算拿10天。
买入前就要想清楚持有逻辑。如果你的持有逻辑只是”短期会涨”，那就是在炒，不是在投资。长期主义是买入逻辑的自然延伸。
💬 原文金句
“股票是由每个买家自己’定价’的，到你’自己’觉得便宜的时候才可以买，实际上和市场（别人）无关。“（来源：投资逻辑篇·第五章第5节，2012-04-14）
“买的时候也一样。买的理由可以有很多，但这只股票曾经到过什么价位最好不要作为你买的理由。我的判断标准就是价值。“（来源：投资逻辑篇·第五章第5节，2010-03-27）
“不打算拿10年的股票一定别去打算拿10天，不然就是’炒’了。“（来源：投资逻辑篇·第五章第5节，2011-12-13）
“买股票和这只股票过去是多少钱没关系，就像卖股票和买入成本无关一样。搞不懂这点就是trader。“（来源：投资逻辑篇·第五章第5节，2012-01-28）
🛠 如何实践
买入前，问自己两个问题：
- 我真的看懂这家公司了吗？ 买入的前提是在能力圈内。看不懂的公司，再便宜也不能买——“如果你没看懂的话，你下的是什么手？”
- 我自己觉得便宜吗？ 不是别人说便宜，不是跌了很多，而是你自己对未来现金流折现的判断告诉你这个价格低于内在价值。如果需要按计算器才能算出来一点点便宜，那就不够便宜（毛估估）。
买入后，只有一件事需要检查：
买入时的逻辑是否还成立？公司的生意模式和企业文化有没有发生根本性变化？如果没有，股价波动与你无关。
⚠️ 常见误区
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❌ “股价跌了很多就是买入机会” — 买入标准是”自己觉得便宜”，而不是”跌了多少”。跌了很多但依然高估的股票不值得买；关键是你对公司价值的判断，而不是价格的涨跌幅度。
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❌ “要等到市场情绪好转、有人接盘时再买” — “投资最重要的一点实际上就是能够忽略市场”。等市场情绪好转再买，往往已经不便宜了。（来源：段永平投资问答录(投资逻辑篇)，2012-02-14）
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❌ “买入前要研究很多公司，广撒网” — “我懂的生意非常少”，10年里只重手投了5家公司。买入的前提是真正看懂，而不是广泛涉猎。
🔗 关联节点
上游概念（理解这个概念的前提）： 买股票就是买公司 · 未来现金流折现 · 能力圈 · 安全边际