Sell high, buy low
— but backwards.
Short selling flips the script: borrow shares, sell first, buy back later. Profit when prices fall, burn when they rise. Play with mechanics, compare with puts, accelerate with margin, and survive the squeeze.
How shorting works
Borrow, sell, buyback, return — the four steps that make a short. Every day you hold, borrow costs accrue.
You borrow shares from your broker, sell them at market, and hope to buy them back cheaper later. The borrow fee is an annualized cost deducted daily — hard-to-borrow stocks can charge 20%+.
You buy back 100 shares at $85 — pocketing $1,500 before fees.
Shorting equities vs. buying puts
Two ways to bet against a stock — one with unlimited loss, one with defined risk and time decay.
Shorting stock exposes you to unlimited loss if the price rises. A put option caps your loss at the premium paid — but decays daily (theta) and requires getting the direction and timing right.
Shorting with margin — the accelerator
Margin lets you short more shares with less cash. But a rising stock erodes equity fast.
Shorting on margin works differently from long margin. Reg T requires 150% of the short sale proceeds as collateral. A rising stock erodes your equity — and the broker can force you to cover at the worst moment.
More cash collateral = higher call price = more room before forced cover. Thin equity on a short is playing with fire.
The short squeeze — when covering cascades
A high-SI stock rising becomes a feedback loop. Each forced cover pushes price higher.
A high short-interest stock that starts rising becomes a pressure cooker. Each round of covering pushes the price higher, forcing more shorts to cover.
- Positive catalyst pushes the stock up — shorts start losing.
- Risk-managed shorts cut losses and buy to cover — pushing price higher.
- Higher price triggers stop-losses on the remaining shorts — more buying.
- Momentum traders pile in, option dealers delta-hedge with more buys.
- The cycle burns until all weak shorts are flushed out or fundamentals cap the move.
Shorting with options — advanced strategies
Bear spreads, naked puts, and ratio spreads — options give you more ways to express a bearish view.
Shorting effectively
Rules the pros follow — and the mistakes that blow up accounts.
- ✓Check borrow availability and fee before entering — expensive borrows eat profits.
- ✓Set a hard stop (buy-to-cover order) at entry — shorts can gap against you overnight.
- ✓Short baskets / ETFs to diversify single-stock blow-up risk.
- ✓Use put spreads when you want downside exposure with defined risk.
- ✓Monitor short interest and days-to-cover — high readings warn of squeeze risk.
- ✗Never short a stock just because it looks overvalued — markets stay irrational.
- ✗Don't short low-float, high-SI names — they're coiled springs.
- ✗Avoid shorting into a strong uptrend — wait for distribution and a breakdown.
- ✗Never add to a losing short — the loss has no ceiling.
- ✗Don't short without understanding the catalyst that proves your thesis wrong.