Google Vulnerable to Shrinking Ad Dollar

An onslaught of cautious analysts' reports has also hurt the stock in recent days, on top of the constant beating the overall market has been taking as a result of the financial sector meltdown. Google shares have fallen 54% from their 52-week high.

Anmuth maintained that Google is undervalued at its current levels. He also noted that "when we look across the rest of the advertising space, we think Google will hold up better than any other name due to its success-based nature and high ROI."

Nonetheless, Anmuth argued for more transparency from Google, especially given the current climate. Although the Internet giant has gotten away with offering scant details about its operations in the past, he called for it to change course, noting that as Google's growth decelerates, investors will no longer see it as a top-line story and will want to know more about the bottom line.

"Google's general lack of transparency and policy not to issue forward guidance was not as much of a concern during its first few years as a public company during its hyper-growth period," he wrote.

"However, with great macro caution, a more highly penetrated business model, and potential foreign exchange headwinds, we think investors need more clarity during this less certain period."