As investors traipse through a truncated summer trading week, volume on the major option exchanges is light.

With many traders and investors taking Thursday and Friday off to hit the links, one would expect a lackluster session. "Expect dull action for the next two days, but that sort of trading usually drifts to the upside," said Larry McMillan, options strategist and head of

McMillan Analysis

.

A floor trader at the

American Stock Exchange

said trading was "very slow" and that today probably wouldn't yield any predictive option activity. However, the trader did say that some investors are buying calls in response to some encouraging news. A call option gives the buyer the right to purchase 100 shares of a stock for a specific price within a given period of time.

For example, online retailer

Amazon.com

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was receiving plenty of attention on the heels of a research note issued by investment bank

Bear Stearns

. "We expect that Amazon's 2Q results should come in well ahead of street consensus on both the top and bottom lines," wrote analyst Jeffrey Fieler. The analyst cited improved operating efficiencies and the effects of first-quarter restructuring efforts as the catalysts for a bottom-line improvement. As a result, Fieler now expects the company to lose 20 cents a share for the second quarter, down from his prior forecast of a 21-cent loss. Wall Street analysts, on average, are expecting a second-quarter loss of 22 cents a share.

"Amazon has pre-released

quarterly figures at the beginning of the second week following the end of the quarter for each of the past two reporting periods, creating a near-term trading opportunity for investors," the analyst wrote in a research note.

As for the option activity, investors were expressing bullish sentiment by snatching up the July 15 near-the-money calls, which traded more than 10,000 contracts on open interest of 11,003. The premium, or cost of the option, was most recently listed at 95 cents ($95), up 45 cents ($45) from yesterday.

Amazon shares traded up $1.06, or 7.5%, to $15.18 at midday.

Meanwhile, the

Chicago Board Options Exchange Volatility Index

, a gauge of investor fear, rose to 22.37. Implied volatility is a key component of option pricing -- the greater the implied volatility, the higher the premium. The index is down 30% for the year.