Falling interest rates and a shortage of housing inventory are heating up the market for home flipping. The rate of home sales that were flips during the first quarter was up 20% across the country compared to a year ago, marking the highest rate of home flipping since the first quarter of 2014. "While responsible home flipping is helpful for a housing market, excessive and irresponsible flipping activity can contribute to a home price pressure cooker that overheats a housing market, and we are starting to see evidence of that pressure cooker environment in a handful of markets," said Daren Blomquist, senior vice president at RealtyTrac. Here's a look at the housing markets where the home flip share of all property sales set new record highs during the first quarter. The data, from RealtyTrac, is based on properties sold in an arm's-length sale for the second time within a 12-month period across 126 metropolitan statistical areas.