As a Citigroup (NYSE: C) shareholder I know that Saudi Prince Alwaleed bin Talal made a killing back in 1991 when he backed up the truck and bought shares of Citi at what was then a low price of $10 a share -- $2 adjusted for splits. He is no doubt unhappy with the 90% drop in the value of the stock since its September 2000 peak of $57.50. Now he's trying for a repeat of his previous success by boosting his share of Citi from 4% to 5%. Unfortunately, it won't work this time.

Alwaleed's stock holdings have plummeted. For example, his Riyadh-based Kingdom Holding Co. has lost 63%, wiping out $13 billion in value. Citigroup, his largest holding, has fallen by more than 75% since January 15, when Alwaleed increased his stake. His concept that Citi is dramatically undervalued does not hold much water. The reason for that is that given its complexity and exposure to derivatives, off balance sheet entities and Level 2 and 3 assets -- which total $36.8 trillion, $1.2 trillion, and $1,195 billion (88.6% of total assets) respectively -- Citi is impossible to value.

Meanwhile, the steps that Citi has taken are not going to be enough to help it survive. Sure it has raised $75 billion by selling assets and equity stakes since December and plans to cut 52,000 jobs. But Citi has only $98.6 billion in common equity, and unfortunately, an 8% decline in the value of those Level 2 and 3 assets will wipe that out. Things are not good for Citi and that does not bode well for Alwaleed or Citi's other shareholders.

Peter Cohan is President of Peter S. Cohan & Associates. He also teaches management at Babson College and edits The Cohan Letter. He owns Citigroup stock.

I can picture Sandy Weill, the former chairman of Citigroup (NYSE: C), now. He's probably pacing the floor of his penthouse apartment, wringing his hands, sweating, perhaps yelling into the phone at someone when he gets a chance. He must be all in a lather about Citigroup's drop in share price (down another 5% so far today to $35.91).

I co-wrote a book about Sandy Weill that came out in 2002 and one thing Mike Brewster and I posited is that Weill would like to run Citigroup until he met his maker. That wasn't in the cards, since he had to step down in 2003 after a series of scandals rocked the bank. And calling Weill the King of Capital, as we did in our book (King of Capital: Sandy Weill and the Making of Citigroup), didn't look so smart not too long after publication either.

Now I've been watching Maria Bartiromo on CNBC reporting that Weill does not want to run Citigroup, but will be happy to help out in the search for a new chief executive. Here's my interpretation: Of course he'd love to jump in and run the company again. He just knows the board could never give him the chance.