Remember this sprawling, 9,600-square-foot home at 1900 North Casey Key Road? It was listed on Feb. 18 for $19.9 million—the most expensive residential listing in Sarasota County at the time.

Well, it sold in a cash deal for $16.5 million, tying for the highest sale ever recorded countywide. Longboat Key’s Serenissima estate sold for the same price roughly five months ago.

The speedy nature of the sale is a sign of a historically strong seller's market in which luxury homes are in high demand. Just in the last 10 days, two homes—one on North Washington Drive and the other in the Quay Commons—each sold for more than $5 million.