Quote from optioncoach:
Not exaclty. The adjustment is put on because the market is moving towards you credit spread and you expect it to keep moving. Assume your credit is $5,000. If the market is falling you might spend more than that rolling down the spread or buying it back.
Adding the bear put spread for a Prego Fly will turn your net credit into a net debit position. You are not risking $25,000 at all, you risk now is the net debit as opposed to the $100,000 you had before. ANy settlement over 1240 you lose the net debit but it is a very small limited risk as opposed to the potential $100,000 risk you faced when deciding to put on the position. Pricing options now, I can turn my 1190/1205 put spread into a $7,000 debit spread Prego Fly.
If I saw the market falling hard I could take $100,000 of risk minus premium received and turn it into $7,000 of risk with a potential for huge profits should the market keep falling. If the market reverses and moved higher than the limited loss is a part of the limited risk hedge I slapped on when I was fearful of a large continued move lower. (like adding a ton of partial hedges and watching the market reverse which is the norm lol).
But the new wronkle is that after converting to Prego Fly, I sell another deep OTM credit spread to finance it and now I have a no cost trade with huge profit potential but still risk with the new credit spread, but now deeper OTM.
This is not a month to month adjustment. This is when I fear the shit is hitting the fan and my strikes are not safe. Instead of adjusting the strikes, I can roll into the Prego Fly. THis might be needed once ro twice a year but I will take the small limited loss potential of the net debit one or twice a year as a risk v. the full $100,000 risk of the example spread. Plus I get the bonus that if the market slides into the belly of the Prego FLY, I coud have significant profits.
So therefore I think your inintial understanding of the numbers was off. If you want a real life example, assume you got 100 1190/1200 for $0.45 and want to add 25 of the 1240/1200 bear put spreads to roll into the FLY. When I last priced it I believe it would be a net debit of $7,000. So you go from risking $95,500 to make $4,500 to risking $7,000 to make $93,000.
The point is that you just do not put it on at anytime. It is when you think the pending market moves could potentially put your spread in danger. So it is a "Break Glass in Case of Emergency" approach.