Whether you are pulling packs, combing through eBay listings for steals, or doing a bit of both, you should always keep in mind what can cause drastic changes to the value of a certain player's cards and what to look for in players who you want to invest in for the future. Here is a list of a few things to keep an eye out for:
1. Lesser known players storming onto the scene: We all knew about Zion coming into this NBA season, but there are some guys the average fan wasn't talking about at the beginning who are now amazing cards to pull/buy low. For example, Ja Morant was not a household name when this season began and probably still isn't to the casual NBA fan. But collectors are dying to get their hands on his rookie cards because he has put together a dominant rookie campaign. Other guys like Rui Hachimura and Trae Young last year were other examples of players like this you should be looking for.
2. No name players who are quietly putting together a solid rookie campaign: These guys are much harder to spot and there is some inherent risk in collecting them as they have not proven it yet. But guys like Keldon Johnson of the Spurs are a great player to invest in because their cards are dirt cheap and they are trending up. It requires an intimate knowledge of the league and teams to speculate on guys like this but it can pay dividends. Pay attention to what coaches are saying about their rookies, and what their actions are saying as well. Rookies who's minutes are trending up and who are getting more practice with the starters are the guys to keep an eye on. A great example is a former Spur you may have heard of, Kawhi Leonard. It took a few years but he has become a true super star. Collectors who bought low on his cards made a killing.
3. Trades and free agent signings: This is where the real tilt is. Blockbuster trades and signings can make card values fluctuate drastically and a savvy collector can make a killing. We are seeing the affects of trades and free agent signings in real time right now in the NFL. Kyler Murray cards have skyrocketed with the acquisition of Deandre "Nuke" Hopkins, with speculation that his addition will take the Cardinals offense to the next level, making Kyler Murray's future even brighter. Another example in the NFL is Chris Godwin cards, which have also shot up since the acquisition of Tom Brady. Based on his rookie performance with Jameis Winston, it seems collectors think he will become an even more dominant force with Tom Brady and the value of his cards are reflecting this.