I am an intermediate-term trend follower. Some call it position trading. I don’t short-sell because studies show that shorting adds approximately zero to a trend-following system. This is because 1) it runs counter to the overall up-trend of markets, 2) you don't reap dividends, and 3) the borrowing incurs a cost. Also shorting opportunities usually come during bear markets, at which times my focus has to be on avoiding bull traps and sensing for the bottom. If I was shorting as well the extra analysis load would distract me.