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Largest option buying in equities so far

David Russell (david.russell@optionmonster.com)

Activision Blizzard (ATVI): Volume surged in the February 10 puts, the February 13 calls and the February 15 calls. Volume was below open interest in all three, indicating that a bullish three-way strategy was closed after the videogame maker reported earnings. ATVI is up 14.34 percent to $13.79.

Dell (DELL): Volume surged in the January and August calls, but volume was below open interest across the board. DELL is off 0.3 percent to $13.49.

SandRidge Energy (SD): An investor bought 12,500 June 6 puts for $1.03 and sold 25,000 June 5 puts for $0.51. Known as a ratio spread, it cost just $0.01 to open and will generate significant leverage in the event of a limited pullback in the share price. SD is down 0.59 percent to $5.91. (See related story )

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