But how do I know that the fate of his biggest positions might be in the balance? First, the ascension of Carl Icahn as a force took a dramatic turn to an even more positive level last week. Apple ( AAPL) soared on his Twitter comments that he has a huge stake in the company, relative to his normal positions -- not relative to the market capitalization as a whole, which is Doug Kass's complaint elsewhere in this site. The simple truth is that Carl's up big on Apple, and that's a testament to his power right now and the belief that no one has a hotter hand. What this means is that, the moment Herbalife issues clean financials (they are only dirty because of the actual rogue actions of the accounting firm doing its auditing), I have to imagine that Icahn will push for an expanded share buyback, or even a Dutch tender offering, that would immediately cause the stock to soar. After the Ackman-led initiative to try to get Herbalife's products taken off the market, or at least tainted in the mind of the public -- and even with The New York Times' huge take-out of the company last week -- Herbalife shares did not get hit. This tells you that, for the moment, without sanctions from the Food and Drug Administration, Herbalife has no reason to fall precipitously. However, it could go up gigantically if the audit is completed on the company's books. Then there's General Growth Properties, the real estate investment trust that helped propel Ackman to the height of the Great Hedge Fund Man universe. This company, resurrected shrewdly by Ackman, dwells in the shopping-mall section of the REITs -- and I think could be hanging by a thread, given the sudden downfall in the overall REIT sector. Every single player in this now-horrendous bond-market-equivalent group has been shelled by the rapid increase in bond yields -- except General Growth. That's despite a dividend yield of just 2.66%, which is far less yield protection than that of better-run companies like Federal Realty ( FRT), Vornado ( VNO), Kimco ( KIM) and Simon Properties Group ( SPG). All of these currently offer yield of more than 3%.