Pitch Me a Short

On a long, your downside is capped at 100% and upside is unlimited. A short is the opposite — gains are capped at 100%, losses are theoretically unlimited if the stock keeps rising. You also pay to borrow the shares (the short selling cost / borrow rate), the position works against you over time via that cost, and a crowded short can trigger a short squeeze. So a short thesis needs more discipline than a long: a clear catalyst and a reason the stock won't squeeze.

Strong reasons a stock falls: (1) Overvaluation with a catalyst — priced for perfection on growth that's about to slow. (2) Deteriorating fundamentals — margin compression, market-share loss, a secular decline (think melting ice cube). (3) Accounting / quality-of-earnings red flags — aggressive revenue recognition, growing accounts receivable outpacing sales, channel stuffing, or adjusted EBITDA that strips out recurring costs. (4) Broken or fad business model with weak unit economics. Note: 'it's just expensive' is the weakest short — rich stocks stay rich for years.

Timing matters far more on shorts because the borrow cost bleeds you while you wait. Name a catalyst: an earnings miss, guidance cut, debt maturity / refinancing wall, lockup expiry, regulatory action, a covenant breach, or a competitor launch. The catalyst is what converts 'overvalued' into 'down 30% in the next two quarters.' Without one, you can be completely right on the fundamentals and still lose money as the stock grinds higher.

Volunteer these or you'll get dinged: (1) Squeeze risk — check short interest as % of float and days-to-cover; a heavily shorted, low-float name is dangerous. (2) Borrow cost / availability — hard-to-borrow names with high fees erode returns. (3) Unlimited downside — how you'd size and stop out. (4) Buyout / takeout risk — a cheap, falling stock can get acquired at a premium, the worst outcome for a short. Acknowledging these is the single biggest signal you actually understand shorting.

Shorts are usually sized smaller than longs and sometimes paired (long a quality peer, short the weak one) to hedge sector/market beta — the core of long/short equity. Mentioning that you'd size it smaller, set a stop, or pair it against a long shows risk discipline that interviewers love.