Quote from LucasX:
Mark, I agree with some of your points but not all. Here are my understanding of every sentence you commented. Correct me if I am wrong.
"If I buy 10,000 calls and you can determine that I paid the 'ask' price, then you know that I am buying, and not selling."
Yes, I can determine that. We can get tick data with time stamp and sale price directly from exchange or other sources. This is not a problem.
"Can you conclude I am bullish? The real answer is 'no.' Here's why:"
My answer is yes and no. Sometimes I guess I can, sometimes like you said it's hard to say. Depends on how much information you had at that time.
I don't get this. You don't have any idea if I am keeping the calls naked long or if I am hedging with enough stock to turn the position bearish. How can you guess what someone does with an option position?
"a) I may be covering a front-month option that I sold a long time ago. If that's the case, you may be able to figure that out when open interest is published tomorrow. But, if its an actively traded option, you are not likely to get that information."
I disagree with you this point. Suppose you sold front-month option long time ago and held it(not covering) until today's bulk trade, then I don't need tomorrow open interest info to figure out you are covering. Why? cause as long as you hold your short option pos, those pos will reflect in the open interest each day after you sold. I can always look back historical open interest and compare those with bulk volume. Tomorrow doesn't matter in this case.
First, you will not see today's chane in OI until tomorrow. It's not published today. It's published once per day, overnight.
Next, if 100,000 contracts trade the same day that I buy my 10,000 contracts, my trade get buried and OI tells you nothing about the 10,000-lot trade.[/B]
"b) Intending to disguise my intentions, I may be selling 1,000,000 shares short, converting my long call position into a synthetic put position. In this case I would be wildly bearish, but you have no way to know if I am selling stock."
Sure, you can selling tons of shares to convert to put. It's a way to make money I agree but it's way risky. My understanding of this play is you first bot huge amount call then sell even bigger amount shares. Run over everyone. What if shits happen you can't sell short anymore or if shares are hard to borrowing, like VW short got crucified.
It is no more risky than buying 10,000 puts. It is equivalent to buying those 10,000 puts. And no, someone in this position does not sell 'way more' stock. You sell 100 shares for each option bought. To hedge 10,000 call, the trader sells no more than 1,000,000 shares.
Now you are being insulting to the call buyer. If shares are hard to borrow, the call buyer would not attempt to sell 1,000,00 shares. f I were the buyer, I would know - in advance - that my broker can get those shares for me, or else I would not make the trade.
I don't mean to question your knowledge, but do you understand that if you own a call and short stick, you cannot get 'crucified,' no matter how high the stock runs? You just lose the value of your puts. In this case, that loss would equal the time premium in the calls.
There is no way to knowing if selling stock? I disagree. Depends on how much you are selling. If 10,000 lots in your example, man, that's a lot. I can easily find out those info from chart's volume or time and sale stamp. Even you initiated a VWAP order, I guess just my guess. It can't be finished in one day for certain low volume stocks.
Do you really believe that a stock that trades 100,000,000 shares per day that you can find my trades? I would not be shorting 1,000,000 all at once. I know that when I buy 10,000 calls, the market makers who sold are likely to hedge with stock. Thus, I;d be selling 100k, 50k, 200k etc. Until filled on my million.
Besides why would you want to make all this effort. Why would you care what I did with my 10,000 calls. Are you going to assume that I know something just because I bought 10,000 shares? Do you plan to 'follow me' and do the same thing? That would be very foolish.
I would never do this in a low volume stock. You cannot assume someone sophisticated enough to hid disguise his trade is an idiot.
"c) I may be taking a delta neutral position by selling just enough stock to be delta neutral. In this scenario, I would have no market bias."
What's the point here? Are you implying they want to do gamma scalping to compensate front month theta loss everyday? Is this a good way to do gamma scalp? I don't know. It's open to debate.
It is NOT open to debate. as you said, you don't know. For a trader who anticipates big volatility in this stock, gamma scalping is a viable, profitable methodology. Nut, the call buyere may also be wagering on a substantial move - in one direction or another and is doing this play instead of buying straddles. It's equivalent to buying straddles.
"d) And, of course, I may simply be taking a long position. Possibly speculative, possibly as a hedge against some portion of my portfolio etc."
It all boiled down to the correlation between a single stock and your portfolio if you intend to use it to hedge your whole portfolio. how do you know that correlation will hold constant? Not mention beta effect. there is a big question mark in my mind that this is a proper way to use a single stock option to hedge your whole portfolio. I might be wrong for this point. has anyone ever heard of this type of hedging, let me know.
Now you are off on a tangent. You said you can determine what I was doing with the options. No one cares if you agree or disagree with the reasoning of the buyer of 10,000 calls. It is irrelevant whether the trader is doing something smart or stupid.
And your argument is exactly why you should NOT care if I, or anyone else buys the calls. I may not know what I am doing and why in the world would you want to follow such a trader? How can it be worth your time to do the research in a feeble attempt to know if I kept, or hedged the calls?
that's all I had to say. Thanks Mark. You brought up a lot of interesting points worth of thinking.
an option newbie
Lucas [/B]