Billionaire Mark Cuban questioned the stock market's safety Friday, bashing perceived apathy toward high-frequency trading.
In a series of tweets, the Dallas Mavericks owner and "Shark Tank" investor implied people care more about alleged wrongdoing in daily fantasy sports than financial market risks. Cuban posed the question, "do you think the stock market is safer today than it was 10 years ago?"
The entrepreneur and investor previously took to his messaging app Cyber Dust to warn about high-frequency trading in August. Cuban advised investors to be careful, as traders making high-volume computer-based bets can make moves more quickly.
The practice notably came under scrutiny in Michael Lewis' 2014 book "Flash Boys: A Wall Street Revolt."
Disclaimer: CNBC broadcasts repeat episodes of "Shark Tank."