Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Chart Industries Inc (GTLS - Get Report), where a total volume of 2,693 contracts has been traded thus far today, a contract volume which is representative of approximately 269,300 underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 93% of GTLS's average daily trading volume over the past month, of 289,580 shares. Especially high volume was seen for the $25 strike put option expiring September 16, 2016, with 1,034 contracts trading so far today, representing approximately 103,400 underlying shares of GTLS. Below is a chart showing GTLS's trailing twelve month trading history, with the $25 strike highlighted in orange:

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Intersect ENT, Inc. ( XENT) options are showing a volume of 3,000 contracts thus far today. That number of contracts represents approximately 300,000 underlying shares, working out to a sizeable 90.3% of XENT's average daily trading volume over the past month, of 332,375 shares. Particularly high volume was seen for the $17.50 strike call option expiring August 19, 2016, with 2,000 contracts trading so far today, representing approximately 200,000 underlying shares of XENT. Below is a chart showing XENT's trailing twelve month trading history, with the $17.50 strike highlighted in orange:

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And FireEye Inc ( FEYE) options are showing a volume of 45,099 contracts thus far today. That number of contracts represents approximately 4.5 million underlying shares, working out to a sizeable 88.7% of FEYE's average daily trading volume over the past month, of 5.1 million shares. Especially high volume was seen for the $23 strike call option expiring September 16, 2016, with 30,419 contracts trading so far today, representing approximately 3.0 million underlying shares of FEYE. Below is a chart showing FEYE's trailing twelve month trading history, with the $23 strike highlighted in orange:

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For the various different available expirations for GTLS options, XENT options, or FEYE options, visit StockOptionsChannel.com.