S&P SmallCap 600 in Focus: SNIC GIFI

Software maker Sonic Solutions took the biggest loss on the Standard & Poor's SmallCap 600 Index at midday Monday after an analyst downgraded the company to "Hold" ahead of its June 10 quarterly earnings report.

The index _ which tracks stocks with a market capitalization between $300 million and $2 billion _ fell 7.35 points, or 1.7 percent, to 387.96. Small-cap companies make up about 3 percent of the total U.S. securities market, but are often cited as good investments due to their low valuations and potential to grow into big-cap stocks.

Canaccord Adams analyst Steven B. Frankel cut Sonic from "Buy" in a note to investors on Monday, saying he is cautious on the company's core and DVD operations. Shares plunged $1.02, or 10.6 percent, to $8.58.

Medical device maker Theragenics Corp. tumbled 39 cents, or 9.9 percent, to $3.54.

Pharmaceutical ingredients maker Cambrex Corp. lost 59 cents, or 9.6 percent, to $5.56.

Among gainers, Gulf Island Fabrication Inc., which builds offshore oil drilling and production structures, soared $4.59, or 8.7 percent, to $44.97 after hitting a fresh all-time high of $46.42 earlier in the session. Oil prices rose $1.67 a barrel to $129.02 on the New York Mercantile Exchange Monday.

Massey Energy Co. climbed $5.23, or 8.1 percent, to $69.85. In a note to investors, Friedman, Billings, Ramsey's David Khani upgraded the coal miner to "Outperform" from "Market Perform," predicting higher coal prices. He also raised price targets for all U.S. coal companies he covers.

Patriot Coal Corp. rose $9.02, or 8.3 percent, to $117.15. Khani named the company a "Top Pick" in his note.