Carla DiBello used to be a reality TV producer in Los Angeles. Now, she's riding mega-yachts and attending business meetings with the world's richest people and is a direct conduit to one of the world's most influential investors: The Saudi Sovereign Wealth Fund. WSJ's Justin Scheck details her rise to prominence.

Billionaire Michael Bloomberg has hugely outspent all other Democratic presidential candidates. His campaign is focusing its resources on Super Tuesday on March 3. WSJ's Tarini Parti and Michael Howard Saul look at whether his high-spending tactics could work.

Runners wearing versions of Nike's Vaporfly shoe have smashed marathon records, leading to questions about whether the shoe offers an unfair advantage. WSJ's Rachel Bachman explains the controversy.