Yahoo valuation after Alibaba went public

Ok Now Alibaba is started trading at around $91 and Yahoo started trading down at around $41. Being 22% share holder of Alibaba, Yahoo supposed to get all the benefits of Alibaba ownership. Why market is trading Yahoo downwards? How much Yahoo is truly worth after Alibaba IPO?
Yahoo owns 523 million Alibaba shares or 22.4% of Alibaba. At $90 Alibaba trading Yahoo’s ownership itself worth $47 billion; after paying whopping 35% tax it should be valued at $30.5 Billion. Yahoo owns 35% of Yahoo Japan. At current market value its worth is $7.7 Billion; again after paying 35% tax its worth is $5Billion. Yahoo has $2.74 Billion cash on its balance sheet; for the past twelve months Yahoo made $1.26 Billion on earnings. At twelve times past earnings estimated Yahoo value is at $14.7 Billion.
If we sum all the parts Yahoo value is way over current trading price.
Alibaba portion of Yahoo (@90) $30,595,500,000
Yahoo Japan $ 5,032,966,784
Cash on Balance sheet $ 2,744,455,000
12 times trailing earnings $14,413,572,000
Grand Total: $53, 086,493,784
Fully Diluted Yahoo shares: 1,095,000,000
Per share Yahoo value: $48.48
Let’s say if you want to ignore earnings metrics and adopt conservative 8 times trailing EBITDA ($1.28 * 8) is at $10.24 billion that puts Yahoo fair value at $ 44.40. Also every dollar change in Alibaba worth $0.34 for Yahoo on after tax basis.
Again this is conservative approach on Yahoo valuation. Yahoo can play Alibaba stake at much tax efficient way such as spinning of Alibaba stake into different entity and allocating new entity shares to shareholders. Yahoo brand itself worth lot more; if someone wants acquire entire Yahoo, Share holders demand much higher price than it is now.
Disclosure: Long on Yahoo.