The only thing that matters in Yahoo’s earnings release

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If there's ever been an a earnings announcement when earnings themselves aren't important, it's Yahoo's fourth quarter.

When the company issues results after trading hours Tuesday, investors will be looking for details of a long-awaited plan to divest the company's stake in Chinese e-commerce company Alibaba Group. That stake accounts for the majority of Yahoo's market capitalization (the company holds about 0.393 shares of Alibaba for every one of its own shares, indicating the stake theoretically is worth $41 of Yahoo's $49 share price).

Large Yahoo shareholders interviewed by CNBC say the stock may rise significantly if the company announces a tax-free spinoff of the stake because it will generate billions of dollars in savings that aren't fully reflected in the current share price. However, if Yahoo only spins off part of the stake or none at all, the share price could decline, they said.

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Yahoo CEO Marissa Mayer indicated months ago that the plan for Alibaba would arrive by Tuesday, and some investors have grown nervous as time has passed without news. Indeed, the price of Yahoo dipped earlier in January amid rumors that the company was considering shareholder-unfriendly actions. Yahoo declined to comment to CNBC.

Blodget to Starboard: Give Yahoo some time

Some shareholders say Yahoo's board of directors could come under pressure if the company doesn't announce plans to spin off the entire stake. The deadline for nominating directors to Yahoo's board is March 27.

Yahoo is technically allowed to disclose its plans for the Alibaba stake at any time. While Yahoo agreed to a one-year lockup period following the Chinese company's U.S. IPO in September, it is now free to disclose its intentions for the stake.

Some Yahoo shareholders may be harder to please than others. One shareholder, Starboard Value, has advocated a tax-free spinoff of the company's stakes in Alibaba and Yahoo Japan, along with a potential merger of the core business with rival AOL.

Starboard has shown it is willing to play hardball with companies that don't take its suggestions seriously. Last year, the activist investor successfully replaced the entire board at Darden Restaurants after the Darden brushed off a suggestion to spin off its real estate business. Starboard declined to comment to CNBC.

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Investors including Starboard have said they are frustrated with Yahoo's strategy of growing through acquisitions that are dilutive to earnings. Earlier in January, Starboard published a letter to the company expressing concerns over a variety of issues, including rumors that Yahoo was looking for acquisitions.

The results are due after the market close and an investor call will follow at 5 p.m. EST.

Disclosure: CNBC has a content-sharing partnership with Yahoo's finance site.