U.S. stocks notched their biggest gains in a week Thursday, pushing the Nasdaq composite index to an all-time high.

The rally came a day after the Federal Reserve suggested that it wasn’t planning to raise interest rates right away. Ultra-low rates over the past six years have helped drive a bull market in stocks that has pushed the market to record levels.

The central bank said Wednesday that it needs to see more improvement in the economy and stronger signs of inflation before lifting rates, reassuring investors.

The Dow Jones industrial average gained 180.10 points, or 1 percent, to 18,115.84. The Standard & Poor’s 500 index climbed 20.80 points, or 1 percent, to 2,121.24.

The Nasdaq added 68.07 points, or 1.3 percent, closing at 5,132.95, surpassing the most recent high for the index of 5,106.59 set May 27.

Most major U.S. stock indexes are up for the year, but the Nasdaq is turning in the best performance. It’s up 8.4 percent, compared with a gain of 3 percent for the S&P 500 index and 1.6 percent for the Dow.

The Nasdaq’s rise has been driven by technology and health care. In a slow-growth world, investors are favoring stocks where earnings will be better than average.