Practice Investing Competition

[foxfox1]

My little sister is in a competition in high school. The competition ends the 2nd week of December. They're going to get $25,000 in play money to invest and the one who's portfolio does the best gets a $250 gift certificate. So, it's an all or nothing thing. They need to pick 5 different stocks. Please post your thoughts on stocks that will have a lot of volatility to give her a real shot at getting the most improvement in her portfolio.
They are allowed to buy one bond and one index fund, but the focus is on most gains.

Thanks a lot.