Covered-call supply, cash-secured puts, and conversion fair value

Reading listed options in portfolio context

Holders of large long-stock books often sell calls on those holdings to collect time decay and seek a higher overall portfolio yield. That covered-call writing is a choice about an existing long-equity book, not a standalone view of implied volatility.

Persistent institutional call selling can add downward pressure that leaves listed calls cheaper than they would be without that supply. A cheaper listed call can then be mistaken for a clean implied-volatility reading.

Cash-secured puts as the close substitute

Opening a covered-call position from scratch is described as sharing nearly the same risk-reward profile as selling a put without already owning the stock. A cash-secured put is that put sale while standing ready to buy the stock.

Covered-call writing against stock already held is the version that typically sits on a large long-equity book. The close substitute for opening the covered call from scratch is the cash-secured put, not a separate volatility forecast.

Why out-of-the-money puts can look richer

One stated reason out-of-the-money puts can price richer than out-of-the-money calls is that a downside panic is treated as more plausible than an upside panic. That is a market-structure observation about the two wings.

Editorial: the richer put wing still does not turn one listed price into an implied-volatility signal. The next check is conversion carry.

Conversion carry as the checkpoint

A conversion is defined as buying the stock, selling a call, and buying a put. The package is nearly delta-neutral, with little room for profit or loss except when the stock finishes near the strike at expiration.

That leftover conversion exposure is pin-risk. Exercise of the short call is then uncertain and the shares can be called away.

Conversion packages are usually quoted within a couple of pennies of a fair value set by interest rates and time remaining to expiration. Those carry-based conversion calculations are described as outweighing model valuations when judging whether listed options look expensive or cheap.

If calls look expensive versus historical volatility, the matching puts are typically expensive as well once the conversion is priced. Implied volatility is useful as a richness or cheapness read only after that conversion carry is checked, because expensive calls and expensive puts often appear together.

A reverse-conversion is the opposite three-legged package. Various participants use it for similar carry and pricing reasons.