i saw the following link

http://mobile.nytimes.com/2016/10/16/opinion/sunday/why-you-should-bet-against-your-candidate.html?smid=fb-share&_r=0&referer=https://m.facebook.com/

it is very logical thing to do in the stck market to achive low volatility of income.

like doing CapM model on your business.

iknow traders do arbitrage between stocks in an industry, i mean something like this.

disclausure i thought on this very little. just wrote it down in drafts.