Yahoo! Inc. (NADAQ:YHOO)’s market value has almost doubled since CEO Marissa Mayer took control of the company. However, a majority of the increase in the stock price is due to the growth in the Chinese internet firm Alibaba Group Holding Ltd. and Yahoo Japan Corp. Yahoo holds a stake in both of these rapidly growing firms. The increased value of Yahoo’s stake in the two Asian Internet firms means that the implied market value of the remaining company has actually contracted during the Mayer’s tenure, says a report in Bloomberg View by Matthew C. Klein.

Yahoo YHOO Value

Alibaba has grown much more than YHOO

According to data from Bloomberg, Alibaba is worth around $153 billion while Yahoo! Inc. (NADAQ:YHOO) is somewhere around $39 billion including it’s 24% stake in the Chinese firm Alibaba. So, when you do the math, you can see Yahoo’s real value is just over $2 billion, which is below that of AOL Inc., Groupon Inc. or even Zynga Inc (NASDAQ:ZNGA).

Given that Yahoo! Inc. (NADAQ:YHOO) also owns a 35% stake in Yahoo Japan, which is now a publicly traded firm valued at $32.3 billion, that means Yahoo’s own business value is “less than nothing,” according to Klein

YHOO has a negative value

In 2012, Alibaba was valued around $35 billion, which implies that Yahoo! Inc. (NADAQ:YHOO)’s stake in the Chinese firm was around $8.4 billion. At that time, Yahoo itself had a market value of around $19 billion. Since then, Yahoo’s market value has risen to around $20 billion while its stake in Alibaba has gained to almost $37 billion. Also, Yahoo’s 35% stake in Yahoo Japan has increased from $7.7 billion as of September 2012 to around $11.3 billion. Going by the market prices and analyst estimates, thew value of the company’s core business has lost $12 billion since Mayer became CEO.

Yahoo’s earning report reflect the fact that the company’s minority stake in Alibaba and Yahoo Japan are hiding the present plight of the core business, “although one could quibble with the conclusion that Yahoo has a negative market value.”

However, Klein did point that the data may be interpreted in many ways, including the possibility that Alibaba and Yahoo Japan may be overvalued, which leads to understating the value of Yahoo’s core business. There is, of course, also the possibility that the Yahoo! Inc. (NADAQ:YHOO) shares are “too cheap.” If this turns out to be the case, then management has to make greater efforts to improve value for shareholders.