Investors cheered Thursday's spate of news from

Affiliated Computer Services

(ACS)

after the company announced

plans to buy back up to 45% of its stock and posted better-than-expected quarterly earnings.

The stock shot up nearly 11% on Friday; it was recently up $6.14, to $63.31.

Wall Street also applauded; Stifel Nicolaus analyst William Loomis upgraded the stock to buy from hold and set a price target of $78. And the analyst boosted his earnings-per-share estimates for the next two years. Loomis doesn't own a stake in the company.

"

The Major positive surprise was the announcement of a 'Dutch tender' offer that could repurchase up to 45% of ACS shares. While this will involve significant leverage for ACS, we believe it is manageable, and ACS will be able to continue to invest for organic and in organic growth," Loomis wrote in a research note on Friday.

Loomis wrote that investors should buy ACS shares "even into today's anticipated strength."

And while UBS analyst Adam Frisch was similarly optimistic that the Dutch tender offer was a positive move -- he also upgraded the stock -- he wrote that the result was the separation of ACS shares from the company's fundamentals, which continued to warrant concern.

Specifically, Frisch noted that the company's quarterly profit included a 12 cents-a-share gain partially offset by restructuring costs, while year-to-date free cash flow fell 6% despite the contribution of recent acquisitions.

"Although bookings and organic revs were ahead of expectations, we have trouble validating them unless the impact from recent acquisitions is included," Frisch wrote. UBS does and seeks to do business with companies covered in its research.

He also suggested the Dutch offer theoretically makes ACS, which has been in play, a more attractive target. "Although the enterprise value likely remains flat (or close to it) the equity will decrease as a percentage of the total, potentially allowing a suitor to acquire the company at a premium to the current share price levels," he wrote.