Trading Pure Alpha

"Make a profit over your total investments in the stock market."

- In-game description

Trading Pure Alpha is an achievement/trophy in Grand Theft Auto V.

Acquisition
This achievement/trophy is unlocked after making a profit from investments made on the in-game stock market, by using websites such as Bawsaq.com and lcn-exchange.com.

The method for doing this is simply to buy shares in a business, then wait for time to pass (completing a mission, for example) then sell the shares if they have gone up in value.