Up and down - that's the best way to describe the New Mutants #98 market. Last year, virtually all the grades lost value, then Deadpool 2 helped push them back up. Now the 90-day averages are slumping, but we've got Once Upon a Deadpool on the horizon. This roller coaster ride can make an investor queasy. 

What makes the market so fickle when it comes to NM #98? Personally, I'm not a fan of characters who break the fourth wall (I realize I'm reading a comic), and I'm not fond of joke characters, but I think where Deadpool truly suffers is from over saturation. For the past few years, Marvel has plastered DP's face on every title they have. Then there's the Deadpool spin offs/ripoffs, such as Gwenpool. There's only so much of a character fans can have shoved down their throats before they revolt. Then again, as much as fans may tire of him in the comics, whenever a new Deadpool movie hits theaters, values jump. That's exactly what we've been seeing this year, and it will likely happen again when Once Upon a Deadpool releases next week.

Prices were at a high in 2016 after the first movie wowed audiences. Not that the comic market wasn't already being flooded with all things Deadpool, but after the film annihilated the box office, Marvel filled store shelves with the "Merc with a Mouth." A year later, the NM #98 grades took a hit. Of the 15 different grades sold in 2017, 10 lost fair market value, including everything from an 8.0 to a 9.8. Granted most did fall by staggering amounts, but the fact is only five didn't take a hit in their FMVs.

Just when it seemed like collectors had reached their fill, Deadpool 2 premiered in May, and the 12-month FMVs went back up. Many of the grades reached or even exceeded their 2016 numbers. In total, 16 grades have sold in the past 12 months, and only two saw a drop compared to their 2017 averages.

Now the roller coaster has taken a sharp dive. Over the past 90 days, eight of the 11 grades sold have fallen in FMV with many dipping below their 2016 averages.

This is how things seem to go with NM #98. Roll out a new movie, and the values go up. Let the new wear off, and fans appear to tire of Deadpool, and those values drop. As an investor, it gets tricky trying to time when to sell. What's more difficult is predicting whether or not Once Upon a Deadpool will stop the bleeding and help the roller coaster to take an upward swing.

If this was a completely new movie with an original story, then it would be a given that values for NM #98 would be on the rise. However, this is a rehash of Deadpool 2, censored and edited to a PG-13 rating. The marketing campaign boasts of new footage and a new character, but will it be enough to boost his first appearance? Considering that Once Upon a Deadpool doesn't have stiff competition at the box office, at least not before Aquaman is released on December 21, it will make a decent profit, and we'll see a spike in NM #98 values.

Here's my advice: if you've been debating putting your NM #98 on the market, now is your time. But if you wait more than a couple of weeks to sell, you might as well wait until Deadpool 3 premieres.