How you handle overachieving players -- as well as those who underperform -- will decide your fantasy fate

By Gene Menez

Buy low, sell high -- and count the wins as they roll in. The similarity to the stock market is one of the reasons that fantasy football is so addictive. But as with a real stock exchange, determining the right course of action with commodities that are over- or underachieving is a skill that requires good instincts and solid information. With that in mind, what follows is SI's evaluation of five players who have dramatically exceeded expectations so far this season, as well as five who have drastically underperformed.

The Overachievers

San Francisco 49ers' RB Frank Gore. Peter Read Miller/SI

First-and-10 More Overachievers 1. Patriots running back Laurence Maroney, a FANTASY PLUS favorite from Day One, is well worth acquiring. Buy. 2. Broncos wideout Javon Walker is healthy, but its always a gamble to rely on one of Jake Plummers receivers. Sell. 3. Wideout Amani Toomers Giants are too good to be trailing (and throwing as often) as they have been. Sell. 4. Jaguars running back Maurice Jones-Drew has impressed while spelling fragile starter Fred Taylor. Buy. 5. With Chad Pennington healthy and the Jets running game subpar, receiver Jerricho Cotchery will thrive. Buy. 6. In seven years Bears tight end Desmond Clark has had one season with more than 433 yards and three TDs. Sell. 7. With the terrible Texans likely to keep falling way behind early, the red-hot Andre Johnson, a 6'3", 219-pound wideout who has caught 20 passes for 253 yards in the last two weeks, should continue putting up big numbers. Buy. 8. Once Terrell Owenss broken finger heals, hell overtake receiver Terry Glenn as Drew Bledsoes go-to guy in Dallas. Sell. 9. One domed stadium plus one offense with red-zone troubles equals a big season for Rams kicker Jeff Wilkins. Buy. 10. Led by linebacker Bart Scott (five sacks, one interception), the Ravens D has returned to the top of the NFL charts. Buy.

REX GROSSMAN QB Bears
He was named NFC Offensive Player of the Month for September (and SI's Peter King wondered if he had gotten "an arm transplant from Dan Fouts"), but fantasy owners should beware. Grossman has had only one huge game?against the Lions, one of the NFL's worst pass defenses, in Week 2?and in the opener against the Packers, whose pass defense is even worse than Detroit's, he threw for just 262 yards and one touchdown.

Recommendation: Sell. Favorable matchups have made him look more valuable than he is, and when the wind starts whipping around Soldier Field in a few weeks, passing will be difficult.

FRANK GORE RB 49ers
New offensive coordinator Norv Turner has helped make Gore this season's most pleasant running back surprise. But Gore, who has rushed for 331 yards and three touchdowns, has also fumbled four times in four games, including twice at the opponents' one-yard line, prompting coaches to insert rookie Michael Robinson on goal line carries.

Recommendation: Buy. Despite Gore's butterfingers, he remains the featured back in an improved 49ers attack and has the potential for some big outings against the likes of the Raiders, Lions, Packers and Cardinals.

CHARLIE FRYE QB Browns
Saddled with a truly offensive O-line and one of the worst running games in the league, Frye has been forced to become a one-man gang. Scrambling for his life, he has thrown for a meager 216.5 yards per game but for seven TDs. A contrarian's note: Against the Ravens in Week 3, Frye did pass for a career-high 298?despite getting sacked seven times?and displayed a growing rapport with receiver Braylon Edwards (five catches, 116 yards, one TD).

Recommendation: Sell. Frye has been gutty, but guts don't earn fantasy points.

LAVERANUES COLES WR Jets
After two straight seasons in which he had fewer than 1,000 receiving yards, Coles has rejoined the ranks of elite fantasy wideouts. With a healthy Chad Pennington under center and a dismal rushing attack, Coles has been the Jets' main playmaker downfield, leading the league in receptions (30).

Recommendation: Buy. Games against the Lions, Texans and Packers ensure that the returns will keep coming.

MARQUES COLSTON WR Saints
Possessing great size (6'4", 231 pounds) and good speed (4.5 in the 40), this seventh-round pick from I-AA Hofstra has been a steal. He leads New Orleans with 20 receptions for 336 yards; moreover, with three touchdowns (including an 86-yarder) he has proved to have a nose for the end zone. In certain leagues he also qualifies at tight end, making him even more valuable.

Recommendation: Buy. He's still a free agent in some leagues; even if he's already taken, he won't cost you much in a trade and his upside is enormous.