The primary driver of fix-and-flip profitability is the size of the price spread, according to an analysis jointly released Thursday by Attom and Backflip.

Home flipping in the first quarter was studied for six major metropolitan areas: Austin, Texas; Atlanta; Boston; Charlotte, N.C.; Dallas-Fort Worth, Texas; and Denver.

According to the analysis, their performance “came down to one key factor: how much room investors had between what they paid, what they spent and what they sold for.”

Backflip is a fintech platform for residential real estate investors, and Attom is a real estate data and analytics company. Together, they paired average purchase and resale prices “with construction budgets, projected after-repair values and payoff timelines.”

The report shows that average purchase and resale price differences led to “significantly different outcomes across markets.”

Boston and Atlanta both posted strong returns. Boston’s margins were the strongest in the analysis, with an average return on investment of 28.4%. It wasn’t an apples-to-apples comparison with the capital of the Peach State, however. While Atlanta generated an average ROI of 27%, its properties came with a lower entry point.

The average purchase price in Boston was $647,456, and the average flipped price was $831,456, resulting in average gross profits of $184,000. Atlanta’s gross profits were 54.3% of Boston’s, averaging $99,921.

The tightest margins were seen in Dallas-Fort Worth, which saw only a 4.3% ROI on flipped sale prices of $437,003 after initial purchases averaging $418,856.

Another regional difference was seen in project durations, which shaped returns “by influencing how quickly investors can recycle capital,” the analysis stated.

Payoff periods averaged about 90 days for Atlanta and Dallas-Fort Worth, which the analysis described as a “relatively fast project turnaround.” The longest average payoff period was seen in Austin at 154 days. The Mile High City averaged 133 days to payoff, “reflecting longer timelines for larger-scale renovation projects.”

“Longer timelines can increase holding costs and reduce overall efficiency, especially in higher-priced markets,” the analysis noted. “Execution speed remains a key factor alongside pricing and holding costs.”