Editor's Note: In this feature from Stockpickr, we highlight lists of stocks that have made new highs, lows or seen other unusual activity.

52-Week Highs: Monsanto ( MON) jumped $2.71, or 4.7%, to $61.01, a 52-week high. A government report showed increased crop planting after a cold spring, causing investor optimism for the seed and fertilizer maker.

Biggest % Gainers: Astea International ( ATEA) rose $2.43 or 43%, to $8.05, Tuesday's biggest percentage gain. The software maker more than doubled revenue and swung to a first-quarter profit.

Rising on Unusual Volume: Shares of Mindray Medical ( MR - Get Report), which develops medical products for the Chinese market, were rising 7.3% on volume almost six times normal. UBS upgraded the stock from neutral to buy, after it reported solid earnings Monday. Shares climbed $1.83 to $26.77.

Biggest % Losers: STEC ( STEC) plunged 25%, the day's biggest percentage drop, after announcing a first-quarter earnings shortfall and cutting second-quarter guidance. Shares dropped $2.03 to $6.10.

52-Week Lows: Amgen ( AMGN - Get Report) slipped $2.06, or 3.7%, to $54.01, a 52-week low. The Centers for Medicare and Medicaid Services said it may limit payments for the company's anemia drugs Epogen and Aranesp in response to increasing safety concerns.

Latest Activist Situations: Relational Investors, in an amended 13F filing originally released in February, disclosed a 5.1 million-share stake in Analog Devices ( ADI - Get Report). The company is set to report second-quarter earnings on Wednesday.

Forum of the day

What stocks are headed downward?, whitemagic asks. Whole Foods Starbucks ( SBUX)? FedEx ( FDX)?

Do you know the answer?

How will Blackstone's secondary offering of more than 22 million shares affect Celanese ( CE - Get Report)?, alan steinberg asks.

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