Three Massachusetts markets ranked among luxury locales with the highest share of vacation homes in the United States: Nantucket, Vineyard Haven and Barnstable Town attracted buyers ready to invest in a second home, according to a new study from Realtor.com.

Researchers used data from the U.S. Census Bureau data to identify markets where a large percentage of housing stock is set aside for seasonal and recreational use. Nationally, 3.3% of homes fall into this category.

By comparison, 55% of Nantucket homes qualified. The median price for a home in Nantucket sits around $4,925,000, while the top 10% of the most expensive homes start at $14,117, 250. The micro-market ranked No. 1 nationwide for the highest share of vacation homes.

Similarly, vacation homes make up 54% of the housing stock in Vineyard Haven, the No. 2 vacation home micro-market nationwide. The median listing price for homes in this market is nearly half that of Nantucket’s at $2,500,000, though the top echelon of these listings start at $8,235,000.

“Both islands sit at roughly 17 times the national vacation-home share of 3.3%, underscoring how much of their local housing economy is built around second homes rather than primary residences,” explained Anthony Smith, senior economist at Realtor.com. “Both of these areas are also pure luxury markets, where even the median home surpasses the national luxury threshold.”

Barnstable Town placed No. 5 by share of vacation homes, despite being classified as a larger metro market. Around 33% of Barnstable Town homes qualified as vacation homes. Buyers fork over a median of $909,450 to live there, with prices for the most expensive homes starting at $3,355,500.