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Why trader is selling puts in Geron

Chris McKhann (chris.mckhann@optionmonster.com)

A huge put sale tops today's option activity in biopharmaceutical company Geron as its shares continue to rally.

optionMONSTER systems show that a trader sold 10,000 October 2 puts for $0.18. That compares to total open interest of 9,335 and a daily average of just 133 over the last month for GERN.

The trader will keep the $0.18 credit as profit if GERN stays above $2 through mid-October. But he or she may also be looking to get assigned and be required to buy shares if they fall below that level, as the effective purchase price would be just $1.82 once the credit from the put sale is included. (See our Education section)

GERN is up 4.97 percent to $1.90 after peaking at $2.06 earlier in the session. The stock was down at $1.50 last Friday but has jumped this week, climbing to new 52-week highs.

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