Understanding the background here is important.<p>A year ago, Yahoo announced that they would spin off their stake in Alibaba (around 30B). Somewhere along the last year, it was determined that the spinoff might incur a huge tax bill, costing shareholders a few billion dollars. Last month, they decided to do a reverse spin-off. Instead of spinning off Alibaba, spin off everything else (which is only worth a few billion). The tax bill on 4B is much less than the tax bill on 30B.<p>In other words, all that would be left after the spinoff is an Alibaba holding company.