Option Writing (Selling)

How it works

When you write (sell) an option, you receive the premium immediately and take on the *obligation* — not the right — to honour the contract if the buyer exercises it. A call writer must sell the underlying at the strike if assigned; a put writer must buy it. Writers profit when the option expires worthless (they keep the full premium), which happens when the market doesn't move enough in the buyer's favour. They benefit from time decay (theta), which erodes the option's value daily in their favour.

The risk profile

This is the inverse of buying. An option *buyer* has limited risk (the premium) and large upside. An option *writer* has limited profit (the premium) but large, sometimes unlimited, risk — a naked call writer faces theoretically unlimited loss if the stock soars. Because of this, writing requires margin, and that margin can balloon if the market moves against you.

In India

Option writing is extremely popular among NSE traders on Nifty and Bank Nifty, especially strategies like selling out-of-the-money options near expiry to capture premium decay. SEBI's higher contract values and stricter margins mean writing now needs substantial capital. Many use defined-risk spreads (selling one option, buying a further one) to cap the downside and reduce margin.

Common mistakes

The classic blow-up is naked option writing — collecting small premiums repeatedly, then losing many times that in a single sharp move (a gap on news, a budget, election results). Writers underestimate tail risk and over-leverage on the comfort of frequent small wins. If you write options, strongly prefer spreads that define your maximum risk over naked positions, keep position sizes modest relative to capital, watch volatility closely (premiums and risk both spike when India VIX jumps), avoid carrying large naked positions across event days and expiry, and always know your worst-case loss before entering rather than after.