NEW YORK (TheStreet ) — Last year turned out to be a good one for the real-estate investment trusts as REITs surged to their biggest gains since 2006, more than doubling the broader stock market.

As the economy continued to pick up steam in 2014, an unexpected decline in interest rates helped REITs outperform the S&P 500 index, producing a total return of 32.3% vs. the S&P’s 14.9%, according to the FTSE Nareit Equity REITs Index.

Moreover, Manhattan saw a record number of commercial investment sales in 2014, as 5,197 properties changed hands for a dollar volume of $55.8 billion, a Cushman & Wakefield report revealed. underscoring the popularity of real estate assets.

The REIT gains highlight the market dynamics that made them a star performer last year. Economists predicted interests rates would climb in 2014, pulling back demand for real estate assets. Instead, interest remained near zero, adding to the profitability and appeal of REITs.

A popular asset class due to generous dividend yields and access to prime assets, REITs specialize in owning or financing a portfolio of properties that generate income from various property rentals.

Ranging from office to retail to residential (among others,) REITs also pay out at least 90% of profits to investors.

Cushman & Wakefield Chairman of Investment sales Bob Knakal — who joined the company after a highly publicized $100 million sale of investment sales brokerage Massey Knakal — says REITs will continue to flourish.

Sitting in the middle of significant REITs transactions in 2014, Knakal’s track record consists of selling over 1,700 properties in New York, generally considered the most recorded in New York City brokerage history, having an aggregate market value of $12.5 billion since 1984. Over the past three years, his firm has sold properties to investors from 51 countries.

TheStreet sat down with Knakal for his take on the REIT sector, the prospect of another record year of real estate transactions, REITs as an investment strategy, and which REIT stocks to look out for in 2015.

TheStreet: REITs were a hit for investors last year, more than doubling the S&P 500. 2014 saw more investment sales hit a record high. Where do you see the REIT market as of right now and how do you think it’s going to perform in 2015?

Bob Knakal: Increasing rent levels in 2015 should bode very well for office REITs. We also expect that the increases in consumer confidence and consumer spending should be a shot in the arm for retail property REITs as well. Underlying fundamentals are getting better and conditions are extremely positive. REITs should do extraordinarily well and that’s what we expect to see in the market this year.