Neenah Paper, Inc. and Silicon Motion Technology Corp.

Tuesday brought another wild day on Wall Street with the major indexes whipsawing throughout the day only to finish up sharply by the closing bell. Several Zacks #1 Rank (Strong Buy) stocks saw big gains on the day.

Neenah Paper, Inc. (NP - Snapshot Report) was one such stock. Shares jumped an incredible 27.0% after the company reported better than expected results for the second quarter of 2011.

Earnings per share came in at 49 cents, beating the Zacks Consensus Estimate by 2 cents. It was a 24% increase over the same quarter in 2010.

Net sales rose 8% to $183 million, above the Zacks Consensus Estimate of $179 million. The overall top line was driven by a 15% increase in the Technical Products segment as both selling prices and volumes were higher.

Expect earnings estimates to rise over the next few days as analysts revise their models.

Based on current estimates, shares trade at a very reasonable 10.6x 2011 earnings.

Neenah Paper produces and sells fine papers and various technical paper products worldwide. It is headquartered in Alpharetta, Georgia and has a market cap of $294 million.

Silicon Motion Technology Corp. (SIMO - Snapshot Report) was another Zacks #1 Rank (Strong Buy) stock surging on Tuesday. Shares soared 22.5% after selling off sharply over the previous five trading sessions.

Silicon Motion Technology Corp. is a fabless semiconductor company with a portfolio of multimedia data processing, storage, and transfer solutions primarily for consumer electronics applications. It is headquartered in Jhubei City, Taiwan and has a market cap of $317 million.

Earnings estimates have been rising strongly for SIMO over the last several months. The 2011 Zacks Consensus Estimate has jumped 17% in the last 30 days and currently stands at $0.74. The 2012 consensus estimate is up 7% over the same period and is currently $0.90, representing 23% EPS growth.

Despite the huge jump in price Tuesday, the valuation pictures still looks attractive. Shares trade at just 13.8x 2011 earnings and sport a PEG ratio of 0.7.

Other notable top performing Zacks #1 Rank stocks from Tuesday include: Home Federal Bancorp, Inc. (HOME - Snapshot Report), which was up 20.6%, Marchex, Inc. (MCHX - Snapshot Report), which rose 18.2%, and Huntsman Corporation (HUN - Snapshot Report), which gained 16.6%.

To see the full list of Zacks #1 Rank (Strong Buy) stocks click here.

Todd Bunton is the Growth & Income Stock Strategist for Zacks Investment Research.

Read the full analyst report on NP

Read the full analyst report on SIMO