There's never a shortage of bears on Wall Street.

Even stellar stocks attract shorts, drawing speculators who bet on falling stock prices and cover their positions when they believe that the carnage is over.

It's been awhile since I went over the list of the most heavily shorted companies and the possible reasons for the bearish wagers.

Let's dive back in by checking out the companies with the largest number of shares sold short as of Jan. 15.

 Company

Jan. 15

Dec. 31

Sirius XM Radio (SIRI)

379.0 million

355.4 million

Nokia (NOK -0.81%)

312.5 million

291.7 million

Frontier Communications (FTR)

213.6 million

212.5 million

Intel (INTC 0.64%)

205.8 million

215.5 million

Bank of America (BAC -0.13%)

164.4 million

186.6 million

Source: Barron's.

Feeding the bears
Now it bears pointing out that short interest actually fell slightly for both exchanges, so it's even more noteworthy that the first three names on the list actually saw their number of naysayers grow through the first two weeks of the month.

Sirius XM is at its highest level of shorting activity over the past year, even though it impressed investors earlier in the month by revealing that it closed out 2012 with 2 million net subscriber additions. Its guidance when the year began called for just 1.3 million net additions.

Nokia continues to be a laggard in the smartphone market, though it did post healthy sales for its Lumia devices during the holiday quarter. However, the shorts won big last week as the Finnish handset maker's stock tumbled when it nixed its dividend.

Frontier Communications may be considered a dangerous short because of its beefy 8.9% yield. Shorts have to account for the dividends. However, skeptics remain for the regional telecom operator, which provides phone, Internet, and television services in underserved rural markets.

Intel is the chip giant that just happens to be the top dog in microprocessors. Intel also packs a payout punch with its 4.3% yield. However, the bet here is that as PCs continue to shrink in popularity, Intel won't be able to improve its position in consumer tech markets that are actually growing.

Finally, we have Bank of America. The "too big to fail" banking giant apparently has plenty of people thinking that it will fail -- or at least temporarily falter. Bank of America is routinely among the most actively traded stocks on the New York Stock Exchange, so it's not exactly a shock to have so many shares sold short.

Waiting is the hardest part
All five of these companies have their challenges, but it's not as if any of them are going away anytime soon. Only Frontier is expected to post a decline in revenue this year.

However, it would be a boring marketplace if everyone was bullish.