Should You Add to a Losing Position
A common interview scenario — a trade has moved against you, and you're asked whether you'd add more risk to it — that tests whether you can separate 'the price got worse' from 'my reason for the trade got worse.'
Prerequisites: Hitting a Risk Limit Mid-Trade
An interviewer describes a position: you bought a stock at $50, it's now at $45, and your original thesis hasn't obviously broken. Do you buy more? This question isn't really about the stock. It's testing whether your reasoning for sizing a trade depends on the price you paid, or on the world as it is right now — and whether you can tell the difference between "this is now cheaper and my thesis still holds" and "I'm trying to make my $50 entry look better."
Two very different reasons to add
There's a legitimate version of adding to a loser: new information arrives that makes the trade better at the new price than it was at the old one, independent of the fact that you're already in it. If you'd size a fresh $45 entry the same way with no prior position, adding is consistent. The size decision is being made from today, using today's facts, and simply happens to increase your position.
There's also an illegitimate version, and interviewers are listening for whether you can name it: adding because you don't want to "admit" the first trade was wrong, or because averaging down feels psychologically like it lowers your cost basis and therefore your pain. Your cost basis is a fact about the past. It has no bearing on whether $45 is a good price today. A trader who adds to make the average price look better is optimizing for their own comfort, not for expected value — and this is exactly the failure mode that turns a manageable loss into a large one.
The test: would you buy it fresh?
The cleanest way to answer this in an interview is to state the test explicitly: "I'd ask whether I'd initiate a new position at $45 with no prior stake, sized the way I'd size any fresh idea. If yes, and my risk limits allow it, adding is fine — the fact I already own some at $50 is a sunk cost and shouldn't change the decision. If I wouldn't buy fresh, then adding is just trying to fix a decision I already made, and I shouldn't do it." Interviewers want to hear that your position size responds to current information and risk limits, not to your P&L on the existing position.
Sizing decisions should be made fresh from today's facts, using the test "would I initiate this position now, at this price, with no prior stake?" Whether you already hold a loser is a sunk cost and should not itself be a reason to add — the reason has to come from new information, not from wanting your average price to look better.
Averaging down without new information is the single most common way interviewees reveal sunk-cost thinking. If your stated reason for adding is anything like "it makes my average cheaper" or "it can't go much lower now," say so out loud that this is not a valid reason — naming the trap is often what the interviewer is actually listening for.
Related concepts
Practice in interviews
Further reading
- Schwager, Market Wizards (interviews on averaging down)