Wachovia shares are down Monday on "crisis psychology" -- but hedge fund master Bill Ackman is optimistic.
Ackman, managing principal of Pershing Square, scooped up a 7 percent stake in Wachovia, or "about 170 million shares," amid the news that Citigroup would buy the troubled financial's banking business.
"We started buying aggressively after the Citi deal was announced," Ackman told CNBC. "What was interesting was citi was buying a subsidiary, but assuming holding company liabilities -- an unusual transaction.
With rules now in effect that boost acquirors' ability to offset losses from bad debts held by other banks, and as a result of the "unusual" structure of the deal, some "very interesting tax attributes" were created -- namely, tax losses that can be carried back or forward.