SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Strategies & Market Trends : Options -- Ignore unavailable to you. Want to Upgrade?


To: rkral who wrote (1400)1/20/2000 3:42:00 PM
From: RoseCampion  Read Replies (1) | Respond to of 8096
 
Your reply proves that one can have an excellent understanding of options without a need to be skilled at the math involved. This is meant to be a compliment .. though somehow it doesn't sound like one.

LOL! No, truly, I agree. I think I have excellent 'practical' math skills, and at this point a decent understanding of at least some of the dynamics of the more straightforward option plays - but never having taken a formal statistics course, my knowledge of the arcana of both terminology and algorithms in the statistical arena is pretty weak. I thus welcome any and all corrections to anything I might say in this forum.

Let me clarify the above. The volatilities for different time periods are related by the square root of the ratio of the time periods involved, as stated in McMillan OSI.

Exactly, as was brought up during the last few days on this thread (prompted by your initial post):

Message 12605898

BTW, this calculation is _wrong_ in the currently-distributed (v0.1A) version of the BlackRose spreadsheet. It only affects the 'informational' display of the first and second standard deviation (cells A13 and A15), not the option valuations themselves, which are correct. I'll fix it in the next 'release', but if you want to do it yourself, I now have cell A13 (in both the 'buy calls' and 'buy puts' worksheets) as:


=INT(D5-D5*SQRT((B6-B5)/365)*$F$5)&"-"&INT(D5+D5*SQRT((B6-B5)/365)*$F$5)


and cell A15 in both as:


=MAX(INT(D5-D5*SQRT((B6-B5)/365)*$F$5*2),0)&"-"&INT(D5+D5*SQRT((B6-B5)/365)*$F$5*2)


Any other feedback or corrections from the users of the spreadsheet is appreciated.

The interesting result of this mathematical exercise is that the expected profit from my covered call position in AOL, on the day it was placed, was about ZERO....Does a number in this area make any sense to anyone?

Perhaps I'm missing something, but isn't the initial profit expectation on any play where the option is currently priced at its theoretically correct level going to be zero? After all, someone is buying that covered call you're selling expecting to make a profit as well - if the option is correctly priced for the stock's current price and volatility, both of your theoretical net profit expectations must start at zero (even though you certainly must have different expectations for the future stock price).

One imperfect analogy would be a raffle where I sell 100 tickets and promise a prize to the winning ticket holder of $100. If the tickets were 'fairly' priced at $1, then although the odds of any one ticket buyer realizing a profit are poor, the total profit expectations of all ticket holders and the ticket seller would both obviously net out to zero. If the tickets were 'unfairly' priced at $2, then my profit expectation as the seller would be higher than the buyers; if at .50, the other way around.

Anyways, if this is true, and I understand your question, then I think it means your formula is perfectly correct (and the slight minus profit expectation is to be expected from having to sell at the bid and/or buy at the ask, the unavoidable effects of the spread).

-Rose-