There was a 17.2 percent increase in single-family home sales in the Bay State in October compared to the same month in 2008, according to The Warren Group.

The spike was the highest year-over-year increase in 2009, which has seen an overall drop in single-family home sales of 1.4 percent. It offers evidence that a federal tax credit for homebuyers — which has recently been extended to April — stimulated the marke