Quote from dummy-variable:
there's a difference between "zero-sum" and "zero-expectancy".
zero-sum indicates a finite system. every withdrawal entails an equal deposit. how those withdrawals and deposits are split doesn't matter. the fact is there is a limited pie and when someone takes a piece, someone else goes hungry.
zero-expectancy has more to do with efficiency and probability. it implies that market forces have converged so that at any given moment the current price offers no economic advantage to either the seller or the buyer.
both concepts are fundamental to trading. zero-sum implies that for every winner there is a loser. it also means that while there will likely be some winners, not everyone can be a winner. with trading, if there are a few big winners, it stands to reason that there are many losers.
retail traders enter every trade with a less than zero-expectancy (i.e. negative expectancy) because of slippage (the likelihood of an order being filled at worse than the mid-point of the bid/ask spread) and commissions.
if every option trade is a negative expectancy wager and the net outcome is zero-sum, it also stands to reason that a trader can only win this kind of game through chance ("luck") or skill.
there is no "strategy" that bestows either luck or skill. strategy is mostly a form of trade selection and set of entry signals. but negative expectancy tells us that no matter how simple or complex the entry strategy might be, it is certain to deliver losses if followed over the long run. yet i'd guess 99% of what is sold as market expertise and advice falls under this category.
if purveyors of market expertise were honest, the first thing they'd tell their clients is, "my strategy is as good or bad as any other, if you follow it, you will likely lose money. in fact, since you are paying my for my advice, you are further aggravating your negative expectancy."
whether you are buying or selling an option doesn't matter. in fact you are better off randomly entering any trade. if you enter randomly, you have no bias and will thus react to the market more objectively. the only way i know to develop skill at trading is to make these random trades and somehow, consistently find a way to make them profitable.
So...zero expectancy means that there is no edge, and zero sum means that there is nothing of value created; just a transfer of wealth from loser to winner.
The zero expectancy point is true for most trading: true arb opportunities are rare.
But I submit that for investors the zero-sum point is wrong: there is a positive expectation. In equities for example I think one can reasonably expect a high single digit return over the long run. T Rowe Price uses 8% in their models. As an investor, you get paid for taking on risk.
In the case of options, what does it mean to be an investor? As I think about it, it also means taking on risk. The buyer of an option lays off risk on the seller. In exchange, the seller gets paid a premium. So the seller in my simple model is the investor.
In an efficient options market, this exchange is made at fair value, net of transaction costs. No trader has an edge.
And embedded in the premium is compensation for the seller in exchange for bearing risk; otherwise, who would do it? The challenge for the options "investor" is to capture this bit over the days until expiry.
So the options investor does not sell high just to buy low (like a trader) but rather to harvest theta. The one prediction that we can make with a very high degree of confidence is that time will flow on.
The mind-set of an options investor is more of a bondholder than a trader. Indeed, I think of my options accounts as comprising a separate, complementary asset class to equities, bonds and real estate. And diversification is one free lunch that is freely available.
Over time I have found that a theta-harvest program can yield 10-20% with some annual consistency...sorta like high yield bonds. If Gallacher is right and this is the "market return" for such a program, well OK by me: I don't expect to beat the market, just get paid by it.
What about options buyers? I think of them as either speculators who want to leverage themselves greater than the 2.0 allowed in margined equities accounts; or insurance buyers looking to lay off risk. Why else would you buy an option?