Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Cardiovascular Systems, Inc (CSII - Get Report), where a total volume of 1,104 contracts has been traded thus far today, a contract volume which is representative of approximately 110,400 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 50.9% of CSII's average daily trading volume over the past month, of 217,075 shares. Especially high volume was seen for the $30 strike call option expiring February 16, 2018, with 1,001 contracts trading so far today, representing approximately 100,100 underlying shares of CSII. Below is a chart showing CSII's trailing twelve month trading history, with the $30 strike highlighted in orange:

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GameStop Corp ( GME options are showing a volume of 21,011 contracts thus far today. That number of contracts represents approximately 2.1 million underlying shares, working out to a sizeable 50.6% of GME's average daily trading volume over the past month, of 4.1 million shares. Especially high volume was seen for the $19 strike put option expiring April 20, 2018, with 7,858 contracts trading so far today, representing approximately 785,800 underlying shares of GME. Below is a chart showing GME's trailing twelve month trading history, with the $19 strike highlighted in orange:

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And Acadia Pharmaceuticals Inc ( ACAD saw options trading volume of 9,724 contracts, representing approximately 972,400 underlying shares or approximately 48.7% of ACAD's average daily trading volume over the past month, of 2.0 million shares. Especially high volume was seen for the $25 strike put option expiring June 15, 2018, with 4,970 contracts trading so far today, representing approximately 497,000 underlying shares of ACAD. Below is a chart showing ACAD's trailing twelve month trading history, with the $25 strike highlighted in orange:

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For the various different available expirations for CSII options, GME options, or ACAD options, visit StockOptionsChannel.com.