This is a very important question. We never predict the win/loss of any single stock.
As a portfolio, a group of stock can minimize the risk of loss expectation. In statistics, any random subsets from the list and full sets performed
same in guaranteeing the bottom line. If choose a subset, you may miss the stocks with significant gains, but if take the full list,
sometimes it would be challenging to keep eyes on all of them in the holding period, thus difficult to catch the right selling time for each individual.