The San Francisco 49ers had a dominant start to the 2023 NFL season with a 30-7 win over the Pittsburgh Steelers, and that means the fantasy football stock for several players is on the rise entering Week 2.

Here's the fantasy football stock up, stock down report for the 49ers as they prepare to take on the Los Angeles Rams.

Stock Up

Brandon Aiyuk (WR):

It's officially Brandon Aiyuk season. The fourth-year wide receiver had a monster performance in Week 1, catching all eight of his targets for 129 yards and two touchdowns, which made the second-highest scoring wide receiver using PPR scoring. How could his stock not be rising after a game like that? You probably shouldn't expect him to produce multiple touchdowns per game, but he's an outstanding playmaker who will continue to thrive in this offense. He has top-15 receiver potential moving forward on what could be the best team in the NFL.

Brock Purdy (QB):

If Aiyuk is going to be dominant, he needs someone to throw him the ball. That's where Brock Purdy comes in. It's no secret that San Francisco is going to run the ball early and often with Christian McCaffrey, but Purdy still has the weapons at his disposal to put up solid fantasy numbers each week. He may not match the output of top-tier quarterbacks due to the focus on the ground game, but there's so much touchdown potential that he's worth an add if you need a streaming option.

Deebo Samuel (WR):

There are some who believe Deebo Samuel is an obvious sell candidate after Week 1. Not so fast, my friends. He played 59 snaps to Aiyuk's 58 and had 11 yards per reception while catching five of seven targets for 55 yards. It was the lack of a touchdown that led to a WR36 finish, not the lack of involvement in the offense. Sure, you're going to want more than 10-12 points every week if you spent a high draft pick on him. But again, this is a dynamic offense that figures to feature multiple players in the spotlight every single game.

It was Aiyuk leading the way against the Steelers in Week 1, so it could be Samuel doing the same thing against the Rams in Week 2. His stock isn't rising based on preseason projections, but it is rising based on the overreaction to one game. You should consider buying him low if another manager is eager to trade him.

Stock Down

George Kittle (TE):

To be honest, George Kittle is probably more of a “to be determined” stock for fantasy managers than stock down since he's been dealing with a groin injury. However, he only had three catches on six targets for 19 yards to finish as TE33 in Week 1, so he kind of has to land in this spot. With McCaffrey, Aiyuk, and Samuel clearly the top three options in the offense, Kittle's production will once again vary each week. Just don't get too discouraged to the point that you drop him since the tight end position is the most unpredictable in fantasy football.

Offenses Who Play The 49ers Defense:

Five sacks, two interceptions, seven points allowed in the Week 1 win against the Steelers. That'll do. Pittsburgh had five consecutive three-and-outs to start the game, and the 49ers should be one of the most productive defenses in the NFL this season. After a divisional showdown with the Los Angeles Rams, it's home matchups with the New York Giants and Arizona Cardinals. This playmaking defense could outscore skill position players in those two games.