Thanos may seem invincible with his six Infinity Stones, but not even the Man Titan can keep values of Invincible Iron Man #55 from falling.

For six years, we were teased with the arrival of Thanos. From the moment he was revealed as the mastermind behind Loki's invasion of New York City at the end of Avengers to both Guardians of the Galaxy movies - not to mention all the Easter eggs and innuendos pertaining to the Infinity gauntlet and the Infinity Stones in practically every other entry into the MCU - fans anxiously awaited the moment Thanos moved into the forefront of the battle.

Although he may not have been the hero, Thanos was Infinity War's protagonist, and he defeated Earth's Mightiest Heroes decisively. With that attention, the Mad Titan became more interesting and more popular than the Avengers, at least for a time. Now that we're only weeks away from the conclusion of Thanos' "decimation" as Marvel has officially dubbed it, we await the villain to get his due.

Last year in anticipation of Infinity War, sales for Invincible Iron Man #55 were setting record highs. While the 12 month averages are still among the highest they've ever been, it's the 90-day fair market values that are cause for concern. Of the 18 different grades that have sold in the past three months, 12 of those have experienced a drop in FMV. Granted these are not plummeting values, and they're still above the 2017 averages, but the prices are nonetheless taking a slide.

From the 9.4 down to the 2.0, most of the grades are on the backslide. The 5.5 has experienced one of the larger drops. Last year, it averaged $516, but over the past 90 days, it's slipped to a 90-day average of $490. Another example is the 7.5, which had an FMV of $755 with a record high of $865 in 2018. This year, it has fallen to a $710 FMV. What's more is that three of the past five sales have been for below $700, which was nearly unheard of last year when, out of 29 total sales, in failed to exceed $700 just five times.

That's nothing to panic about, clearly, but it's the fact that so many other grades are beginning to lose value that is worth watching. But why?

This could be due to what we all know is inevitable in Endgame: Thanos is going to die, and the indication from Marvel Studios is that his defeat will be at the hands of Captain Marvel. That fact could be driving collectors away from Iron Man #55 since it's clear that his role in the MCU is coming to an end, and it's a mystery as to who will be taking his place. However, Thanos is still a major villain in the comics continuity, so it's not like his character will vanish completely. As we know, the market is driven more by the MCU than by the comics, which is kind of sad if you ask me. Still, it is what it is.

As a fan of Thanos, I am excited about the possibility of finally adding an Iron Man #55 to the collection. I'm under no false impression that it will suddenly drop to record low prices, but I predict that we will see a more significant fall in sales following the release of Endgame.