Updated from 1:02 p.m. EDT

Ambassadors Group ( EPAX) was among the Nasdaq's winners Tuesday, jumping 6.6% after the provider of education travel services posted second-quarter earnings that topped Wall Street's forecast.

The company earned $20.9 million, or $1.05 a share, on net revenue of $42.9 million. Analysts polled by Thomson Financial expected earnings of 99 cents a share. During the year-earlier quarter, the company earned $18.5 million, or 86 cents a share, on net revenue of $35.2 million. Shares closed up $2.23 to $36.25.

Harte-Hanks ( HHS) slumped 9% after the direct-marketing company posted second-quarter results that disappointed investors. The company earned $22.9 million, or 31 cents a share, on revenue of $290.1 million. Analysts expected earnings of 33 cents a share on revenue of $296.8 million. During the year-earlier quarter, the company earned $30.2 million, or 37 cents a share, on revenue of $298.4 million.

Looking ahead, Harte-Hanks said that it is unlikely that it will post earnings comparable to last year's $1.39 a share. Analysts project full-year earnings of $1.38 a share. The company called the outlook "disappointing" and said that results would be "far below" the expectations the company had when it started the year. Shares closed down $2.36 to $23.77.

Shares of Idex ( IEX) fell 4.1% after the industrial goods company posted mixed second-quarter results. The company earned $41.6 million, or 51 cents a share, which was in line with analysts' expectations, on revenue of $344.5 million, which was lower than expected. Analysts expected earnings of 51 cents a share on revenue of $347.1 million. During the year-earlier quarter, the company earned $35 million, or 43 cents a share, on revenue of $296.6 million. Shares closed down $1.60 to $37.69.

Domino's Pizza ( DPZ) jumped 16% after the pizza delivery company posted better-than-expected second-quarter results. The company posted earnings of $2.3 million, or 4 cents a share, on revenue of $340.3 million. Excluding items, the company earned 28 cents a share. Analysts expected earnings of 24 cents a share on revenue of $337.8 million. During the year-earlier quarter, the company earned $24.5 million, or 39 cents a share, on revenue of $327.7 million. Excluding items, the company earned 34 cents a share in the year-ago quarter. Shares closed up $2.93 to $21.21.

Shares of Corn Products International ( CPO) rose 4.7% after the food ingredients company posted second-quarter results that easily beat expectations. The company earned $50.6 million, or 66 cents a share, on revenue of $857 million. Analysts expected earnings of 57 cents a share on revenue of $770.8 million. During the year-earlier quarter, the company earned $30.1 million, or 40 cents a share, on revenue of $644.9 million.

Looking ahead, Corn Products now sees full-year earnings of $2.35 to $2.55 a share. Analysts project earnings of $2.30 a share. Shares closed up $2.01 to $44.80.