These are the stocks posting the largest moves before the bell.Market Insiderread more
Oil fell on Tuesday after surging the most on record following attacks on Saudi's oil industry that disrupted the kingdom's production.Marketsread more
Damage to the top OPEC producer's oil facilities ignited fears of supply disruption around the world and has sent crude prices soaring.Energyread more
The second-largest investor in Kraft Heinz Company discloses that it has again trimmed its stake in the food company.Marketsread more
Retailers could be in for a jolly jump in holiday sales despite headwinds like the U.S.-China trade war and threat of another economic slowdown.Retailread more
Canaccord Genuity's Tony Dwyer says Americans are spending less than ever on their fuel needs.Trading Nationread more
After a series of setbacks on the road to an initial public offering, the parent company of real estate start-up WeWork is delaying the move, sources told CNBC Monday.Technologyread more
NBCUniversal's new streaming service will be named "Peacock," the company announced Tuesday.Technologyread more
Apple isn't trying to blow our minds with groundbreaking new features on the iPhone 11, but is making lots of little improvements each year, this year focusing on cameras and...Technologyread more
Here are the biggest calls on Wall Street on TuesdayInvestingread more
"I am convinced that at some point later this year we'll see the first 25 basis point rise. It'll rip through the infrastructure of utilities, and REITS and real estate," said O'Leary, one of the stars of the reality show "Shark Tank."
For example, if a couple took a $200,000 loan for a $250,000 house, that house would have to go up 6 percent a year to cover the debt, transaction fees and taxes, he said. However, after five years, O'Leary doesn't think that home will be worth more than the original sale price of $250,000.
Read More Low rates do nothing for mortgages
"Don't buy any real estate. Don't do it," O'Leary said.
Instead, he thinks investors should rent their homes and spend their money in the market—50 percent stocks, 50 percent bonds—for a better return and more liquidity.
Mortgage rates fell last week, as did applications for refinances and home purchase loans. Pending home sales were just up 0.4 percent in April, according to the National Association of Realtors, and the S&P/Case-Shiller composite index showed home prices jumping in March.
—By CNBC's Michelle Fox