Option contracts have two kinds of value, time value and intrinsic value. On the last day before expiration, a put seller has a few possibilities for dealing with near but in the money puts. By afternoon, the put contract has only intrinsic value and time value has fallen to nothing.
A person can do the following: (1) do nothing and accept assignment; (2) buy back and take a new position with more time value. I had the following two experiences:
The PWE (Pennwest Energy) June $23 was near the money, but as long as it was within a few cents, the price to buy to close remained 10-15 cents. But when the price of the underlying dropped to $22.75, I was able to buy back the put at 25 cents plus commission 2.7 cents; and then sold the October 23 at 2.273 after commission. So I cleared roughly $2.00 per share by rolling over and I never received assignment. The assignment would have been 6.1 cents per share, so that the two commissions of 2.7 cents were less than the commission at assignment. So that was a consideration. But then, if I waited until after assignment for the shares to go above $23, I figured that the PWE October $23 would lose also a little time value and little intrinsic value–though this could depend on other factors such as implied volatility.
The PGH (Pengrowth Energy) July $13 put was about to expired in near money. Last week I was a volunteer our church’s Vacation Bible Camp, and I came home on Friday morning to deal with it. First, I wanted to sell an January $13 put to replace it, then buy back the expiring put. But when I used the Questrade platform I made the mistake of buying a put instead of selling. It is a new platform for me, and I was being a little careless. But all of these DIY platforms default to a certain option, and so you must physically change it if you do not want “to buy open”. I think that there should be no default option, but the programmers never talk to traders, I guess. Immediate panic set in and it took me two tries to sell these back (as I didn’t put in the correct number of shares the first time) but finally at a loss of only 6 cents per share (including three commissions!) I was able to exit a position that I never intended to hold. At that point I had no more time and I had to return to the camp. In the afternoon, before market close, I went to buy back my July $13 put, but the underlying (PGH) was at $12.75 and had therefore 25 cents intrinsic value, but the ask price was 40 cents. Unwilling to pay 15 cents above intrinsic value, I let it expire and took assignment. Then, two trading days later I sold my shares at $13.05, which provided me a small profit after all commissions (2.35 cents). I then sold a PGH January $13 put $1.185. Now on Friday, I probably could have sold the same put at $1.335, so that the difference between what I got on Tuesday and what I would have gotten on Friday was 15 cents (including all commissions). This seems the same as my loss on Friday had I rolled it over then, but it has to be remember that (1) I would have paid 3.5 cents commissions to roll it over that day, and I made 2.35 cents profit on selling the assigned shares. So I saved 5.85 cents which almost pays for the 6 cent blunder that I made. So the net profit was 1.185+.0235-.06 (blunder)=$1.149. On Friday, I figured that I could have only cleared as much as $1.15 before commissions so I was happy with how it finally played out. So it was a wash in the end, despite my careless trading on Friday.
So I guess the lesson in these two scenarios is that it is good to buy back an option on expiry if you can get it for intrinsic value. The commission cost on assignment would easily offset the commission costs of buying back and selling the new position. But if market will not sell at intrinsic value, it is probably just as well to take your chances with assignment, particularly if you are still bullish on the underlying security. The advantage of PGH is that it’s 7% monthly dividend would have more than paid margin interest charges–so even if it takes months for it to return to the strike price, you are able to cover all the carry charges.