Mr Market is Benjamin Graham's parable for the stock market's daily quotations. Imagine a business partner who appears each day offering to buy your stake or sell you his, at a price driven by his mood. He is there to serve you, not to instruct you, and you are never obliged to trade.
The parable
Graham introduced it in The Intelligent Investor and Warren Buffett has called it the single best idea about investing ever written down. You own a share of a business alongside a partner. Every day he names a price at which he will buy you out or sell you more. Some days he is euphoric and names an absurdly high price. Some days he is despairing and names an absurdly low one. His mood has nothing to do with how the business is performing.
The point is not that he is always wrong. It is that his quotation is an option you may exercise, never an instruction you must obey.
What it actually changes
It inverts the meaning of volatility. In most of finance, price movement is the definition of risk. In Graham's framing, a falling price on an unchanged business is not risk but a better offer, and the investor with a longer horizon is being handed something by the investor with a shorter one.
That is only true if you can tell the business from the quotation, which is the harder half. It requires some estimate of intrinsic value arrived at independently of the price, and the discipline of a margin of safety so that being roughly wrong is survivable.
The way it is misused
Mr Market has become an all-purpose excuse for ignoring bad news. Every falling stock has holders explaining that the market is being irrational, and sometimes it is, and sometimes the market noticed something first.
The test is whether anything in the business changed. A price that fell on no news, or on news about the sector rather than the company, is genuinely Mr Market. A price that fell because customers are leaving, margins are compressing or the moat is narrowing is the market repricing new information, and calling that irrational is how people hold losers for years. The honest version of the parable requires you to look for the news before concluding there is none.
Using it in practice
The practical form is a watchlist with prices attached. Decide what you would pay for a business you understand, write it down while nothing is happening, and let the quotation come to you. Deciding in advance is what makes the offer usable, because in the moment a falling price feels like information rather than an opportunity.
It also argues for checking prices less often. A partner who visits daily is harder to ignore than one who visits quarterly, and nothing about the underlying business changes at the speed the quotation does.
Judge the business, not the quotation
Stock Simplifier lays out the fundamentals for any US stock so you can see whether anything actually changed before the price did. Free to start.
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Frequently asked questions
Related
- Intrinsic value, the independent estimate that makes the quotation usable.
- Margin of safety, the discipline that makes being roughly wrong survivable.
- When to sell a stock, how to tell a changed thesis from a changed price.
- Circle of competence, knowing the business well enough to judge the offer.