LOS ANGELES — Mitch Guttenberg says he was born to run a trading card shop.

"I started collecting cards when I was 4-years-old, and this is always what I wanted to do," he said.  

He co-owns The Bullpen around the corner from LAX and has never been busier. Before the pandemic, the store was open from noon to 10 p.m. Now, it's only open from 2-7, but that hasn't really mattered.

"There is more action walking into the store from 2 to 7 than we ever had from 12 to 10," Guttenberg said. "Over the last year and a half, it's been absolutely insane, the amount of prices and cards from every sport, baseball, basketball, hockey, golf."

Many sports fans, stuck at home during the pandemic, got out their old card collection and discovered a renewed interest in buying and selling trading cards for big money. Social media is packed with videos of young fans ripping open packs of cards to see what value they can score. 

In a TikTok video, a young fan said he bought a LeBron James rookie card for $9,000. 

"Call me crazy, but I think this is going to hit $20K," he said.

"I really had time to focus on it and turn it from a hobby to making [a] profit from it," said Jordan Gendron, a rap artist who found himself out of work when the pandemic hit.

"Things have been a lot harder for artists, so a lot of us have been doing stuff like this to supplement the income," Gendron said.

In the past year, he said he raked in about $100,000, but he had to do a ton of research.

"Because there [are] so many people coming into the industry and so much more money coming into the industry, everything goes up…so quickly!" Guttenberg said.

At any one time, Guttenberg said there are more than 18,000 boxes of cards, also known as wax, in his store. He said that's more than any other store of its kind in the country. One of the most expensive cards in his collection?

"Luka Dončićs autographed rookie from flawless," Guttenberg said. "This card's probably getting close to $200,000."

There are only 15 of them in the world.

Guttenberg then took out a box of cards that retail for about $50 at stores like Target and Walmart, but on the resale market, go for $900.

"You can pull a card that's over $1,000 in here, and it's not a needle in a haystack anymore," Guttenberg said.

In fact, prices are fluctuating so quickly the store will only guarantee them for 12 hours instead of a week, and sadly, many kids just looking to collect are getting priced out of this popular pass time, so Guttenberg tries to help.  

"We just give cards away to these kids. I mean, it's just become such a big thing. Every kid should collect cards," he said.

But for Guttenberg, this world of sports trading cards is about more than just price, it's about passion.

"You tell me what you're looking for. I will help you find whatever you possibly can," he said.

It's a passion he loves sharing with any sports fan who stops by.