The slow melt-up to record highs continued Thursday for the S&P 500 amid economic optimism.

The Dow rallied 131 points. The S&P 500 rose 22 points to close at a record high for the sixth straight day. The Nasdaq gained 18 points.

This is a steady-as-it-goes market, says Victoria Fernandez, she's chief market strategist at Crossmark Global Investments.

"We do think the markets are going to continue to trend higher. Now, that doesn't mean we're going to see the same 14 percent return that we saw in the first half of the year for the S&P. I think it will be maybe a little bit less than half of that if I try to look into my crystal ball and see what's going to happen. But look, we still have quite a bit of liquidity. The Fed isn't going anywhere quickly in regards to tapering, in regards to hiking rates."

The number of Americans filing new claims for unemployment benefits took a big drop last week. First-time jobless claims fell to 364,000, a fresh 15-month low. While job cuts are easing, employers are finding it hard to hire new workers. Even in Republican-led states where extra jobless benefits have been curtailed, Americans don't appear to be in a rush to go back to work. A clearer picture of the labor market will be revealed Friday with the crucial monthly employment report.

Manufacturing activity continued to grow in June, albeit at a slower pace than the month before. A lack of available workers to hire appears to be slowing down operations.

On the corporate front: Walgreens Boots Alliance beat sales forecast and raised earnings expectations for the year, but the stock dropped when the drug store chain forecast weaker vaccinations for the current quarter. Shares of Walgreen's shed more than 7 percent.

One day after getting slapped with a record regulatory fine, Robinhood announced plans for an IPO in a regulatory filing. The trading app will list on the Nasdaq under the ticker symbol HOOD, in one of the most anticipated stock market debuts this year.