(CBS) — Stocks closed lower on the first trading day of August as soft economic data, declining crude oil prices and negative developments overseas weighed on equities.

The S&P 500 lost 6, the NASDAQ dropped 13 and the Dow Jones Industrial Average closed down nearly 92 points, settling to 17,598.

“The sell-off in Greek stocks and Puerto Rico’s historic default weighed on U.S. markets right from the start of today’s session,” says Chris Lissner, president and partner at Acropolis Investment Management. “Declining oil prices are also a factor here and we expect continued pressure on the energy sector.”