Short Sale Rules and Restrictions
Short selling is permitted and constrained. The constraints are specific, they change during stress, and they affect what is possible rather than what is advisable.
MadStockAlerts Research · Updated August 28, 2026
What to take away
- A locate is required before a short sale in most circumstances.
- The alternative uptick rule restricts short selling after a large intraday decline.
- Regulators have imposed temporary bans on shorting specific sectors.
- Close-out requirements apply to persistent failures to deliver.
- Restrictions constrain the mechanics rather than the view.
MAD Academy Training Video · 0:46
Rules That Only Bind When It Falls
Short selling carries restrictions that activate under stress — a price trigger, a locate requirement, and occasional outright bans.
This lesson is part of a Stock Alerts + Tools plan.
The locate requirement
Before selling short, a broker must have reasonable grounds to believe the security can be borrowed and delivered by settlement. That is the locate, and it is why hard-to-borrow securities are sometimes unavailable to short at any price.
A locate is not a guarantee. A borrow arranged today can be recalled tomorrow if the lender sells, which is the mechanism behind forced buy-ins described in the securities lending article.
The alternative uptick rule
If a security falls ten percent or more from the previous close, a restriction applies for the remainder of that session and the following one: short sales may only be executed at a price above the prevailing national best bid.
- 1The security falls 10 percentFrom the previous close
- 2The restriction activatesFor the rest of the session and the next one
- 3Short sales must be above the bidWhich means resting rather than taking liquidity
- 4Longs are unaffectedThe restriction applies only to short sales
Temporary bans
Regulators in several jurisdictions have at times prohibited short selling in specific securities or sectors, most prominently in financials during the 2008 crisis. Studies of those episodes have generally found that they widened spreads and reduced liquidity without supporting prices.
For a holder, the practical point is that the rules can change while a position is open. A short that cannot be maintained because the activity has been restricted is a position closed by regulation rather than by a view.
What none of it changes
- The asymmetry of the payoff, which is a property of the position rather than of the rules.
- The borrow cost, which is set by supply and demand rather than by regulation.
- The recall risk, which follows from the lender's rights.
- The margin requirement, which the broker sets and can raise.
Every one of these is a larger constraint on a short position than any of the rules described above. The restrictions govern how a short may be executed; the economics govern whether it can be held.
Naked shorting, and what the rules address
Selling short without having borrowed or located the shares is generally prohibited, and the term is used loosely enough in public discussion that it is worth separating the categories.
| Situation | Status |
|---|---|
| Short sale with a locate obtained | The ordinary case, and permitted |
| Short sale with no locate | Prohibited under Regulation SHO for most participants |
| A market maker hedging in the course of bona fide market making | A narrow exception exists, with conditions |
| A failure to deliver arising operationally | Not a violation in itself; close-out requirements apply |
| Persistent failures in one security | Triggers the threshold list and mandatory close-out |
The fourth row explains most of the failure-to-deliver data that is quoted in support of stronger claims. Failures arise from ordinary operational causes and are usually resolved within days, and the data alone does not distinguish those from anything else.
The threshold list, close-out requirements and failure data are all published, which makes this one of the few areas where a claim about market structure can be checked directly against a regulator's own record.