周選價平賣方之迷思
https://steadyoptions.com/articl ... negative-gamma-r86/
Going with close expiration will give you larger theta per day. But there is a catch. Less time to expiration equals larger negative gamma. That means that a sharp move of the underlying will cause much larger loss. So if the underlying doesn't move, then theta will kick off and you will just earn money with every passing day. But if it does move, the loss will become very large very quickly. Another disadvantage of close expiration is that in order to get decent credit, you will have to choose strikes much closer to the underlying.
As we know, there are no free lunches in the stock market. Everything comes with a price. When the markets don't move, trading close expiration might seem like a genius move. The markets will look like an ATM machine for few weeks or even months. But when a big move comes, it will wipe out months of gains. If the markets gap, there is nothing you can do to prevent a large loss.
Does it mean you should not trade weekly options? Not at all. They can still bring nice gains and diversification to your options portfolio. But you should treat them as speculative trades, and allocate the funds accordingly. Many options "gurus" describe those weekly trades as "conservative" strategy. Nothing can be further from the truth.
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