24/7 Wall St.

It is Friday, and the markets have been shaky for the past couple of weeks. Investors should be concerned about which stocks are bringing opportunity and which ones may bring peril. Investors frequently get to see the analyst upgrades and Buy ratings from Wall Street firms, but they often do not get to see is when analyst downgrade stocks to sell or to avoid. 24/7 Wall St. reviews many fresh research calls each and every day to find great ideas from value stocks to growth stocks to dividend stocks, and we have broken out the negative analyst calls today. These are this Friday’s top analyst downgrades and cautious research notes from Wall Street.

Alcoa Inc. (NYSE: AA) was downgraded to Underperform from Neutral at BofA/Merrill Lynch.

Colgate-Palmolive Co. (NYSE: CL) was downgraded to Hold from Buy at Argus.

Maxim Integrated Products Inc. (NASDAQ: MXIM) was downgraded to Equal Weight from Overweight at Morgan Stanley.

Nordstrom Inc. (NYSE: JWN) was downgraded to Neutral from Buy at Sterne Agee.

ON Semiconductor Corp. (NASDAQ: ONNN) was started as Underweight at Morgan Stanley.

Portugal Telecom SGPS S.A. (NYSE: PT) was downgraded to Neutral from Buy at Goldman Sachs after earnings; ADRs trade at $3.85 against a 52-week range of $3.47 to $5.91.

STMicroelectronics N.V. (NYSE: STM) was downgraded to Underweight From Neutral at HSBC.

Credit Suisse has some mixed views on two key silver miners after earnings and after the 18% run-up in silver.