DALLAS - Newcomer Luka Doncic is carving out all-time records on an almost-nightly basis for the NBA's Dallas Mavericks.

Old-timer Tom Brady continues to do the same in the NFL, most recently as the quarterback of the Super Bowl-winning Tampa Bay Buccaneers.

But they have something else in common: Both athletes are at the pinnacle of a growing sports card and memorabilia market, as all-time records have been set for the most expensive basketball and football cards ever sold.

That's about Luka. And that's about Brady.

A week ago, an autographed, one-of-one Luka Doncic rookie card from the 2018-19 Panini National Treasures set sold for a whopping $4.6 million, apparently the second-highest recorded card sale of all time.

And then, a few days later, an autographed 2000 Playoff Contenders Tom Brady rookie card sold for a record $1.32 million, which is believed to be the highest price ever paid for a football card.

READ MORE: Mavs Luka Doncic Quiet In Second All-Star Outing

Doncic, participating in Sunday's NBA All-Star Game in Atlanta, was asked about the phenomenon. 

“4.6 is a lot of money,'' he said. "You can buy a lot of things for that ... I was really surprised. I really appreciate it.''

See more of his reply below ...

Why is this happening? It has been suggested that maybe the pandemic has left more people home-bound, with more time on their hands to pick up hobbies - though most quarantined folks cannot afford hobbies that cost $4.6 million. It has also been suggested that it is all about nostalgia ... though given the fact that Luka is but 22, it's likely not about his past, but rather his future, that makes him worth the investment.