Investors frequently get to see the analyst upgrades and Buy ratings from Wall Street firms. They often do not get to see when analyst downgrade stocks to sell or to avoid. We review 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.

AngloGold Ashanti Ltd. (NYSE: AU) was cut to Sell from an already cautious Neutral rating at Goldman Sachs.

Annaly Capital Management Inc. (NYSE: NLY) was cut to Equal Weight from Overweight at Evercore.

Bed Bath & Beyond Inc. (NASDAQ: BBBY) was downgraded to Perform from Outperform at Oppenheimer.

HollyFrontier Corp. (NYSE: HFC) was cut to Hold from Buy at Cowen.

Lululemon Athletica Inc. (NASDAQ: LULU) was cut to Neutral from Outperform at Wedbush.

MBIA Inc. (NYSE: MBI) was cut to Strong Sell from an already cautious Hold rating by S&P Capital IQ late on Thursday.

MercadoLibre Inc. (NASDAQ: MELI) was cut to Neutral from Buy at Bank of America/Merrill Lynch.

PetSmart Inc. (NASDAQ: PETM) was cut to Perform from Outperform at Oppenheimer.

Sysco Corp. (NYSE: SYY) was cut to Sell from an already cautious Hold rating at Cantor Fitzgerald.

Valero Energy Corp. (NYSE: VLO) was cut to Hold from Buy at Cowen and started as Neutral at Credit Suisse.

Verisk Analytics Inc. (NASDAQ: VRSK) was cut to Market Perform from Outperform at Baird.

Here are today’s top analyst upgrades and positive research calls.