When financier George Soros makes a play, traders stand up and take notice. In 1992, Soros made $1 billion by selling the British pound.

Recently, he used the same strategy of betting against the pound. However, when the pound traded below $1.40 last Wednesday, Soros decided to cover his short position. The pound has traded up to $1.4256 against the dollar on Friday. As demand for the pound rose, it had the effect of putting pressure on the U.S. dollar.

The short interests in both Sirius Satellite Radio (NASDAQ: SIRI) and XM Satellite Radio (NASDAQ: XMSR) fell in May. At Sirius, it dropped 29.1 million shares to 91.3 million. At XM, the decrease was 6.4 million shares to 24.5 million. Sirius had the biggest drop in shares sold short in May than any other stock traded on the Nasdaq.

The shorts have made a lot of money on the two satellite radio stocks this year, and perhaps they believe that at current prices they are not likely to go lower. A look at the pattern in share prices show that this might be true. On January 16, Sirius shares were $4.16. They now trade at $2.80 but have been fairly flat since late April, so perhaps they have found a bottom.

XM is also trading sideways after a big drop. On January 16, the stock closed at $17.14. It has dropped to under $12, about where it traded in mid-April.

The euphoria over the merger of the two companies has evaporated as the FCC and Congress have shown some resistance to approving the deal. They are concerned that it would create a monopoly, which would raise prices to consumers. In addition, the first quarter reports from both companies showed that they are still losing money and burdened with debt.

Perhaps both stocks have found a floor because if the shares went much lower there would be nothing left to trade.

Douglas A. McIntyre is a partner at 24/7 Wall St.

McDonald's Corporation (NYSE:MCD) seems like a very nice company, notwithstanding the fact that it sells a lot of food that can give you coronary artery disease. The company's quarterly earnings were excellent. Revenue went up 10% to $5.88 billion, and net income rose at an even better rate to $843 million.

After all the good news, McDonald's stock moved to a 52-week high of over $42. The stock has been as low as $31.48 in the last year.

So, why does McDonald's have the largest increase in short positions of any stock traded on the NYSE? Not only was the increase large, it was spectacular. Shares short in McDonald's went from 13.1 million to 60.5 million in the month ending in mid-October.

For a short position in a large company to rise 20% or 30% is not odd. But for it to increase by a factor of four times is almost unheard of.

McDonald's stock has not been this high in over six years. And, if it adds a few dollars, it could hit an all-time high. That, by itself, may be a reason to believe that the stock could come down some. Just a little bad news can take shares back a few rungs once they have had such a substantial run.

But if McDonald's continues to do well, whoever bet against them could lose a lot of money.

Douglas McIntyre is a partner at 24/7 Wall St. He does not own securities in companies that he writes about.