How a mistaken trade creates an opening
A stock price is not a verdict on a company’s true worth. It is the price at which a buyer and seller are willing to trade right now, based on what they know, expect, or believe. If someone buys after misreading news, or sells in a burst of fear, that order can push the price away from what more careful analysis suggests.
That gap creates an incentive for another trader. If a stock seems too cheap, the trader can buy it and profit if the price later rises. If it seems too expensive, the trader may sell shares they already own—or, where short selling is possible, borrow shares to sell and hope to buy them back more cheaply. In either case, acting on the discrepancy adds a counterweight to the mistaken trade.
Why being right is not enough
The correction is not automatic. A trader who spots a mispricing still has to risk money, and the price can move further the wrong way before it changes. The trader may have misunderstood the business, or the market may simply have new information that is not yet widely understood. Short selling also has practical limits and can expose a trader to large losses if the price keeps climbing.
So the opportunity is not a guaranteed profit; it is a wager that the market’s current price will eventually move closer to a better-supported estimate. Traders who take that wager help prices absorb competing judgments rather than reflecting only the latest wave of enthusiasm or panic.
The market’s useful disagreement
A market needs people willing to take the other side of trades, including trades driven by poor information. Their orders give informed traders something to respond to, and the possibility of profit motivates those traders to do the work of checking the price. The mistaken trade supplies the opening; the risk-bearing response helps correct it.
