Four percent of all U.S. single-family home sales in the first quarter were flips, sold for a second time within a 12-month period, according to RealtyTrac's first quarter 2015 U.S. Home Flipping Report. It marked the lowest number of homes flipped since the second quarter of 2011, when just 3.4 percent of all single-family home sales were considered flips.

Read more: Housing Flips May Start to Flop

In the first quarter, the average gross profit – the difference between the purchase price and the flipped price – for completed flips was $72,450, according to RealtyTrac’s report. That represents an increase from $65,290 in the previous quarter and is the highest level since the first quarter of 2011.

"The strong returns for home flippers in the first quarter demonstrates that there is still a need in this recovering real estate market for move-in ready homes rehabbed to more modern tastes, particularly given the dearth of new homes being built," says Daren Blomquist, vice president at RealtyTrac. "The challenge for flippers in 2015 will be finding inventory to flip. Flippers ideally want to buy distressed homes that provide them with an opportunity to add value in markets where there is good affordability and ample demand from buyers for the finished flip product — whether those buyers are millennials becoming first-time homebuyers, baby boomers purchasing their present or future retirement home, or buy-and-hold real estate investors looking for turnkey rental properties that cash flow."

According to RealtyTrac's report, investors saw some of the largest returns on housing flips in the first quarter in Baltimore; Deltona-Daytona Beach-Ormond Beach, Fla.; Ocala, Fla.; Lakeland, Fla.; Detroit; Tampa; Pittsburgh; Memphis, Tenn.; and Chicago.

Meanwhile, the following markets are where flips accounted for the highest percentage of all home sales in the first quarter:

• Memphis, Tenn.: 10.6%
• Ocala, Fla.: 8%
• Miami: 7.9%
• Tampa, Fla.: 7.4%
• Sarasota, Fla.: 7.2%
• Los Angeles: 6.6%
• Detroit: 6.5%
• Las Vegas: 6.3%
• San Diego: 6.1%
• Virginia Beach, Va.: 5.9%
• Jacksonville, Fla.: 5.9%

Source: Realty Trac