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

Biggest % Gainers

:

Ventana Medical Systems

(VMSI)

soared 48% Tuesday, after Swiss pharmaceutical giant

Roche

said it wanted to buy the company for $75 a share. The medical instrument and supply maker's shares soared $24.69 to $76.43 at Tuesday's close.

Rising on Unusual Volume

: Ventana's rise was fueled by trading almost 18 times the stock's average.

52-Week Highs

: Ventana's close also was a 52-week high.

Biggest % Losers

:

W Holdings

( WHI) sank 37%, after the operator of Westernbank Puerto Rico said in a

Securities and Exchange Commission

filing that one of its larger asset-based loans is "impaired." The bank said collateral is valued at least $80 million below the value of the loan. It also said it hasn't yet determined its ultimate financial impact. The stock closed down $1.87 to $3.14.

52-Week Lows

: W Holdings' close also was a 52-week low.

Latest Activist Situations

: William Ackman's Pershing Square Capital disclosed it held a 1.9-million-share stake in

Legg Mason

(LM) - Get Report

at the end of the quarter ended March 31. Pershing Square disclosed the stake Tuesday. The asset manager's shares closed up $2.39, or 2.5%, to $99.13.

Forum of the Day

When should one sell

Apple

(AAPL) - Get Report

?

Some say it would be wise to reduce one's position prior to the iPhone launch on Friday,

karen offen says.

Do You Know the Answer?

Is

Freeport McMoRan Copper & Gold

(FCX) - Get Report

a good buy right now? What's causing it to dip?

, badgerinvestor asks.

Feeling Lucky?

And finally, try picking a random portfolio suited to do-it-yourselfers with more detailed analysis at

I'm Feeling Lucky

.

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