Buying Logic
Only buy when you yourself feel it’s cheap — regardless of the market (others)
📌 Concept Analysis
Buying Logic = Only buy when you consider it cheap (price below intrinsic value); the judgment criterion is company value, independent of stock price history or market sentiment.
When buying tomatoes at the vegetable market, you have a mental price — if it exceeds 3 yuan per jin, you won’t buy. Regardless of whether yesterday was 2 yuan or 5 yuan, regardless of whether others are scrambling to buy, you only look at whether today’s price is worthwhile. This is exactly Duan Yongping’s logic for buying stocks — buy when you feel it’s cheap, regardless of how others see it.
💡 Core Understanding
1. The sole criterion for buying is that you feel it’s cheap, regardless of the market.
Stocks are “priced” by each buyer themselves — it’s not others saying it’s cheap, not that it’s fallen a lot, but rather your own judgment of 未来现金流折现 (discounted future cash flow) tells you this price is below intrinsic value. Only when you can truly ignore the market has your understanding of 价值投资 (value investing) reached the proper level.
2. Buying is unrelated to stock price history; there’s only one judgment criterion: company value.
What price levels this stock previously reached shouldn’t become a reason for buying. Similarly, selling is unrelated to purchase cost — 卖出逻辑 (selling logic) and buying logic are integrated; both only look at the company itself.
3. Buying stocks means buying companies — think as if buying the entire company.
Before purchasing, ask yourself: if I had enough money, would I be willing to buy out the entire company? This question helps you return to the essence of 买股票就是买公司 (buying stocks means buying companies), rather than looking at a piece of paper that goes up and down.
4. If you don’t intend to hold a stock for 10 years, definitely don’t plan to hold it for 10 days.
Before buying, clarify your holding logic. If your holding logic is merely “it will rise short-term,” then you’re trading, not investing. 长期主义 (long-termism) naturally extends from buying logic.
💬 Original Quotes
“Stocks are ‘priced’ by each buyer; only when you ‘yourself’ feel it’s cheap can you buy — in reality, this has nothing to do with the market (others).” (Source: Investment Logic Chapter, Section 5.5, 2012-04-14)
“Same when buying. There may be many reasons to buy, but what price this stock previously reached had best not serve as your reason for buying. My judgment criterion is value.” (Source: Investment Logic Chapter, Section 5.5, 2010-03-27)
“If you don’t intend to hold a stock for 10 years, definitely don’t plan to hold it for 10 days, otherwise that’s just ‘trading.‘” (Source: Investment Logic Chapter, Section 5.5, 2011-12-13)
“Buying a stock has nothing to do with its past price, just as selling a stock has nothing to do with purchase cost. If you can’t understand this point, then you’re a trader.” (Source: Investment Logic Chapter, Section 5.5, 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 能力圈 (circle of competence). Companies you don’t understand, no matter how cheap, shouldn’t be bought — “if you don’t understand it, what kind of bet are you making?”
- Do I myself feel it’s cheap? Not because others say it’s cheap, not because it’s fallen a lot, but because your own judgment of 未来现金流折现 tells you this price is below intrinsic value. If you need to press a calculator for half a day to figure out it’s slightly cheap, then it’s not cheap enough (毛估估).
After buying, there’s only one thing to check:
Does the logic from when you bought still hold? Have there been fundamental changes to the company’s 生意模式 (business model) and 企业文化 (corporate culture)? If not, stock price fluctuations are none of your concern.
⚠️ Common Pitfalls
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❌ “Stock price falling a lot = buying opportunity” — The buying standard is “you feel it’s cheap,” not “how much it fell.” Stocks that fell significantly but remain overvalued aren’t worth buying; what matters is your judgment of company value, not the magnitude of price changes.
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❌ “Wait until market sentiment improves and someone takes over before buying” — “Actually the most important point in investing is being able to ignore the market.” Waiting for improved market sentiment before buying usually means it’s no longer cheap. (Source: Duan Yongping Investment Q&A (Investment Logic Chapter), 2012-02-14)
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❌ “Before buying, research many companies and cast a wide net” — “I understand very few businesses”; in 10 years I’ve only made heavy investments in 5 companies. The prerequisite for buying is truly understanding, not casting a wide net.
🔗 Related Nodes
Upstream Concepts (prerequisites for understanding this concept): 买股票就是买公司 · 未来现金流折现 · 能力圈 · 安全边际
Downstream Concepts (conclusions derived from this): 卖出逻辑 · 集中投资 · 平常心
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