Real estate stocks were a buying opportunity a few years ago, but at this point Goldman Sachs Group Inc. says the area is too risky for investors.

At the end of this month, Real Estate will separate from Financials to become its own sector in the S&P 500. While those stocks have outpaced the S&P 500 so far in 2016, analysts led by David Kostin at Goldman Sachs say there are a lot of challenges, and they are not recommending investors try to make up for the missed gains. 

"Real Estate has outpaced the S&P 500 by 156 basis points year-to-date, which has hurt large-cap mutual fund returns given their underweight allocation to the sector," Kostin and company write. One thing that could help the new sector, however, is that even if those fund managers just move from underweight to neutral, there could be a big inflow of funds. According to Goldman, close to half of large-cap core funds managers have zero exposure to the sector. 

The analysts forecast as much as $19 billion in new demand, as funds that aren't currently in real estate try to play catch up. That may be good enough not to slap a sell rating on these stocks, but it isn't enough to give them a buy rating.

"Looking forward, we recommend a Neutral weighting to the Real Estate sector given slowing top-line revenue growth, average relative valuation, and risks from a higher interest rate environment," they conclude. 

This article was provided by Bloomberg News.