Tronox (TROX), InterOil (IOC), First Majestic Silver (AG) and Inovio Pharma (INO)

The market constructed a second straight day of gains on Wednesday thanks in large part to some decent reports from ADP and the ISM. There was also some less-than-horrible news out of Europe that officials may be preparing to aid that continent's struggling banks.

The Zacks #1 Rank Top Performers List certainly shared in the enthusiasm of the session. Today the list included four stocks that gained in the double digits.

Tronox Inc. (TROX) was at the apex of the Top Performers List Wednesday with a gain of nearly 14.5%. Volume more than doubled to around 476,000 shares from the daily average of about 231,000.

There’s only one analyst covering this titanium dioxide producer; nonetheless, the Zacks Consensus Estimate for this year has advanced 3% in the past two months to $17.53, while next year has increased 22% to $31.77 in that time.

TROX uses titanium dioxide through a chloride process technology that yields pigments for paint, coatings and plastics. The company benefited from strong global demand for the pigment, especially in the Asia-Pacific markets, during the second quarter.

The company, which emerged from bankruptcy on Feb 14, announced a more than 21% positive surprise for the quarter with sales that increased 42.4% year-over-year to $428.3 million.

InterOil Corporation (IOC - Snapshot Report) was right behind TROX with a gain of 13.5%. The company was probably making up some lost ground from yesterday when it dropped by more than 10%.

IOC explores, appraises and develops crude oil and natural gas properties in Papua New Guinea. There's been some concern recently about its LNG (liquid natural gas) project, in which the company is looking for a partner to satisfy guidelines from the government of Papua New Guinea.

For now though, the two analysts covering this company have been moving estimates in the right direction for 2011. The Zacks Consensus Estimate has advanced sharply to 48 cents per share from 16 cents in the past 2 months. The outlook for 2012, which has four analysts, has been steady at 30 cents.

It was a good day for metals, as First Majestic Silver Corporation (AG - Snapshot Report) can attest. It gained 10.3% today. AG is involved in the production, development, exploration and acquisition of mineral properties with a focus on silver in Mexico.

The past month has seen both analysts covering the company raised their estimates. As a result, the Zacks Consensus Estimates for 2011 and 2012 are $1.36 and $2.24, respectively, marking gains of 21.4% and practically 10%.

Rounding out the double digit gainers on Wednesday was Inovio Pharmaceuticals, Inc. (INO - Snapshot Report). It had absolutely no room to spare, as shares gained an even 10%.

Through subsidiaries, INO engages in the development of synthetic vaccines for cancers and infectious diseases. It recently won the Edward Jenner Poster Award First Prize for its research to develop a therapeutic synthetic vaccine for cancer.

As is often the case for pharma companies, the six analysts that cover INO are expecting losses for both this year and next. But this is a Zacks #1 Rank, which means that those losses have been narrowing of late.

The Zacks Consensus Estimate for this year calls for a loss of 12 cents, but two months ago it was expected to lose 16 cents. Similarly, next year's expected loss of 15 cents has narrowed 4 cents in that time.

Read the full analyst report on INO

Read the full analyst report on IOC