Uncovered Put Writing

Uncovered put writing means selling a put option without setting aside the full cash needed to buy the shares if the buyer exercises the option. "Writing" a put is the act of selling that put to someone else, which obligates the seller to buy the underlying stock at a fixed price (the strike price) if the buyer decides to exercise it. When the seller backs that obligation with the full purchase amount sitting in cash, it's called a cash-secured put. When they don't, it's uncovered — sometimes called a "naked" put.

The mechanics: the put seller collects a premium upfront in exchange for taking on the obligation to buy shares at the strike price, regardless of how far the stock price falls. If the stock stays above the strike, the option expires worthless and the seller simply keeps the premium. If the stock drops below the strike, the seller can be forced to buy shares at a price well above the current market value, taking an immediate loss offset only partially by the premium they collected.

The nuance that trips people up is thinking "uncovered" means unlimited risk the way an uncovered call does. It doesn't — a stock can only fall to zero, so the maximum loss on an uncovered put is capped (strike price minus premium received, times the number of shares). But that cap can still be a very large number relative to the small premium collected, which is why brokers treat uncovered puts as a margin position requiring collateral, not just a cash trade. The amount of margin or cash a broker demands to let a trader do this, and whether they allow it at all, depends on broker policy and regulatory margin rules that vary and change over time.

People also confuse "uncovered" with "unhedged" more broadly — uncovered specifically refers to the absence of a full cash reserve or an offsetting short stock position tied to that specific put, not to the trader's overall portfolio risk.