Microsoft cofounder Paul Allen owned 2 pro sports teams before he died in 2018....

• Speculation is mounting that late Microsoft cofounder Paul Allen's pro sports teams could be sold.

• Nike founder Phil Knight already submitted a $2 billion bid for the Portland Trail Blazers.

• Allen's trust has sold off other assets, including property and a yacht, since his death in 2018.

When Microsoft cofounder Paul Allen died in 2018, he left behind a collection of assets ranging from multimillion-dollar properties to a 414-foot megayacht.

While much of it has been sold in the years since, two expensive — and high-profile — holdings remain: the NBA' Portland Trail Blazers and the NFL' Seattle Seahawks.

The fates of Allen's pro sports teams have been unclear since his death, when his trust passed into the hands of his sister, Jody Allen. Jody Allen hasn't given a single interview in the intervening years, which means there are few clues about the future of the two teams.

But speculation is mounting that both teams could be sold off to fulfill the terms of Paul Allen's estate, and sold off in the near future. With both teams valued at or above $2 billion, there's a small pool of moguls wealthy enough to submit a bid — and one famous exec has already made an offer.

Here's what we know about Allen's estate, and the future of his teams.

Allen made his fortune building Microsoft with Bill Gates

Paul Allen and his Microsoft cofounder, Bill Gates, met in high school and founded the company in 1975 — it was Allen who coined the name "Microsoft."

Allen left the company in the early 1980s after being diagnosed with non-Hodgkins lymphoma. In the decades that followed, he spent his time as a philanthropist, donating millions, and pursuing his hobbies, like exploring shipwrecks, music, collecting art and mansions, and, eventually, purchasing the Blazers and the Seahawks.

At the time of Allen's death, Forbes placed his net worth at $20 billion.

He bought the Portland Trail Blazers in 1988

Allen paid $70 million for the Blazers back in the late 1980s and promised to keep the team in Portland — today, the Blazers are valued at $2.05 billion, according to Forbes.