My retirement account (a traditional IRA) will let me write a covered call, where I sell a call option if I have the underlying securities (for instance, 100 shares of IBM). The shares are required to be held in case the call I sold is exercised.
They will not allow me to sell a "covered put" where the cash is held to purchase the 100 shares if the owner of the put option exercises it.
I'm particularly interested in using this as a long term purchasing plan: selling a covered put with an expiry 1-3 months out and that is already "in the money", expecting it to be exercised by the purchaser. When it is exercised, I'll have purchased it for less than if I bought it on the current market.
Is there some form of risk associated with this idea that I'm missing? Or is it a regulatory provision for retirement accounts?