CNBC's Diana Olick looks at the rise of home flipping again and how it is different this time around.
DIANA OLICK: That may be a warning sign of an overheating housing market. A new report RealtyTrac puts some big numbers on this big, but risky business. Close to 180,000 single-family homes and condos were flipped in 2015. A flip here is defined as a home that is bought and sold within the 12 months. Flips made up 5 1/2 percent of all sales last year, and that is the first increase in the flip share after four years of shrinking.