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by ikeboy 3689 days ago
Another way of looking at it:

Shorting is (roughly given efficient market assumptions) equivalent to buying a put and selling a call at the same strike. If the stock has no chance of going up a lot, the call will be relatively cheap, and so selling the call won't change much.

Edit: on the other hand if it has low volatility in both directions, then both are cheap, and it's a bit more complicated. Buying the put will be cheaper, but shorting will also require less margin because the margin provider will have less risk. (See e.g. http://openmarkets.cmegroup.com/3785/understanding-margin-ch...).

This should cancel out in theory, but might not for various reasons like transaction costs.

2 comments

Just look at the payoff graphs. This is how options are explained and tested in finance classes and they are usually more accessible than textual descriptions.

http://i.investopedia.com/inv/articles/site/short_vs_put.gif

This link is simple and doesn't point out strike price or take transaction fees into account but you can draw similar graphs that do.

Yes, that's a futures (or forward) trade. Doing the whole thing as a forward would be cheaper than trading a put and a call.