U.S. stocks had their worst day since the war with Iran started, as doubt took over again from hope on Wall Street about a possible end to the conflict.

The S&P 500 fell 1.7% Thursday. The index is headed for a fifth straight losing week, which would be the longest such losing streak in almost four years. The Dow Jones Industrial Average dropped 1%, and the Nasdaq composite sank 2.4%.

They’re the latest flip-flops for financial markets this week after Iran rejected a U.S. offer for a ceasefire. Oil prices rose more than 4%, and Treasury yields climbed in the bond market.

On Thursday:

The S&P 500 fell 114.74 points, or 1.7%, to 6,477.16.

The Dow Jones Industrial Average fell 469.38 points, or 1%, to 45,960.11.

The Nasdaq composite fell 521.74 points, or 2.4%, to 21,408.08.

The Russell 2000 index of smaller companies fell 43.06 points, or 1.7% to 2,493.32.

For the week:

The S&P 500 is down 29.32 points, or 0.5%.

The Dow is up 382.64 points, or 0.8%.

The Nasdaq is down 239.53 points, or 1.1%.

The Russell 2000 is up 54.87 points, or 2.3%.

For the year:

The S&P 500 is down 368.34 points, or 5.4%.

The Dow is down 2,103.18 points, or 4.4%.

The Nasdaq is down 1,833.91 points, or 7.9%.

The Russell 2000 is up 11.41 points, or 0.5%.