House flipping has reached its 10-year high, with gains reaching an average of up to $100,000 per flip, recent reports say.

According to Redfin, as reported by HousingWire, house flipping gains in 2015 rose to $102,400 per home from the previous year's $98,500 and from $90,900 in 2005 housing boom. The increase in gain was recorded despite the reduction in the number of homes flipped to 43,000 homes compared to 2005's peak of 95,000 homes.

Redfin ranked the top 10 neighborhoods that had the biggest gains from home flipping. Securing the No. 1 spot is Petworth in Washington, D.C., which recorded a gain of $337,000 per home flipped. Mount Washington in Los Angeles, California is trailing behind with $312,000 per deal, followed by Silverlake, also in LA, with a gain of $307,000.

Coming next at No. 4 is another Washington, D.C. neighborhood, Brookland, which recorded a profit of $290,000. Rounding up the top five of the hottest markets for house flipping is North Sunnyvale in San Jose, California with $268,000.

The rest of the list include: Brightwood (Washington, D.C.), $261,000; Richmond (Portland, VA), $260,000; Del Ray (Alexandria, VA), $255,000; Ballard (Seattle, WA), $247,000; and Los Feliz (Los Angeles, CA), $241,000.

Home flipping pertains to the purchase of a house for renovation and then reselling it with the aim of generating income in a short span of time. While the increase in the rate of returns is good news for house flipping investors, some experts have expressed concerns over the recent trends. As previously discussed here on Realty Today, some experts think that the increases are sending signals of a troubled housing market.

It has been noted that when house flipping reached its peak in 2005, two years later the mortgage market collapsed, the banking sector experienced crisis and then the recession happened.

Matthew Gardner, chief economist at Windermere Real Estate, said, house flipping sales "artificially inflate home prices, making housing even less affordable for buyers and increasing the risk of a bubble."