NEW YORK, Aug. 14 (Xinhua) -- U.S. stocks traded on an upbeat note on Tuesday as investor sentiment was lifted as the Turkish lira rallied off a record low in the previous session.

At midday, the Dow Jones Industrial Average jumped 109.97 points, or 0.44 percent, to 25,297.67. The S&P 500 was up 18.50 points, or 0.66 percent, to 2,840.43. The Nasdaq Composite Index increased 50.94 points, or 0.65 percent, to 7,870.64.

The Dow's triple-digit gains were led by rallying Walgreens Boots Alliance and McDonald's stocks. Shares of the companies rose, 2.59 percent and 1.44 percent, respectively, around midday.

All the 11 primary S&P 500 sectors advanced at midday trading, with materials and industrials leading.

Tech rose more than 0.5 percent, underpinning the tech-heavy Nasdaq.

A rebound of Turkish lira eased fears about the financial crisis; however, concerns over contagion in emerging economies remained.

On economic front, U.S. small business optimism index marked its second highest level in the survey's 45-year history at 107.9, rising to within 0.1 point of the July 1983 record-high of 108, the National Federation of Independent Business (NFIB) reported on Tuesday. The index measures the opinion of small businesses on the economic conditions in the country. Enditem