Fear that rising interest rates would drive borrowing costs skyward sent a shock through the stock market last week — and that volatility rippled through real estate stocks.

The Dow fell 666 points Friday, concluding the steepest week-to-week point drop since the 2008 housing crisis, and the largest percentage drop, 2.5%, since June 2016, CNN reports.

Experts attribute the abrupt fall to growing concerns regarding rising rates. The Federal Reserve signaled it could increase rates several times this year. January’s strong jobs report coupled with a 2.9% annual jump in wages triggered a bump in the 10-Year Treasury yield to 2.85% last week. This represents a four-year high, according to CNN.

"The key for the market today is rising interest rates," U.S. Bank Wealth Management Managing Director Mike Baele told CNBC. "The old adage is: 'Bull markets don't die of old age, they are killed by higher interest rates.' That looms large.”

U.S. homebuilders' stock also took a dive Friday due to a sell-off by investors fearful of rising borrowing costs. That was the ninth consecutive day of the homebuilders' free fall, Bloomberg reports. Last year, homebuilding companies’ stock performed four times better than the broader stock market.

Commercial real estate investors are similarly wary of rapidly rising interest rates, which can translate to higher borrowing costs and a jump in commercial property pricing.

The industry continues to ride the waves of one of the longest economic expansions in the country’s history. Investors remain cautious regarding the length and age of this cycle, and are tracking sector fundamentals closely in search of signs of a coming correction.