This is year two for me and I have always heard the market skyrockets when a collection drops, but I have yet to see it. What I feel like I have most often seen is a crash, followed by a steady rise the days following. My assumption is that there are a few factors contributing to that...
There is almost always a significant amount of new content that drops with the collection.
The collection seems unattainable for many.
It was not a player that many felt was worth the cost.
But then as the dust settles and the content drop is not as fresh, people start to realize they are closer than they thought and see areas where they need to fill gaps and specific series start to rise (typically postseasons and 2nd half).
I don't pay attention to streamers at all, but I fully expect it to be a big requirement. I had virtually every card in the game for Brett and Cutch, but I was not able to lock either in the second it dropped. I had to either collect some XP to get henchmen or buy a few of the new cards that were hitting the market. I think with Brett I had every single postseason card available, but after the content drop I was needing something like three more because there were so many postseason available in that program. With Cutch there as something like an Always Intense pack that day that had a handful of Milestone cards and even though I had all Milestone before the drop, I was short because of how many were in that pack.