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Even with all the political and geopolitical turmoil, and with the bull market more than eight years old, the major indexes are still near all-time highs. And short sellers may be keeping an eye on two of their favorite stocks in the days ahead. That’s because Sirius XM Holdings Inc. (NASDAQ: SIRI) just missed hitting a new 52-week high a few days ago and has pulled back since, and Yahoo! Inc. (NASDAQ: YHOO) just reached a 52-week high after a more than 10% surge on Thursday. Note that both of these are among the most shorted stocks traded on the Nasdaq.

The more than 252.10 million Sirius shares short on May 15 was less than 1% higher than on April 28, the previous settlement date. It was only the fourth period so far this year in which the number of shares short has grown, and the most recent figure represented 16.9% of the total float. As the average daily volume plunged from a year-to-date high, the days to cover jumped from less than six to nearly 10.

Warren Buffett remains an investor in Sirius during, both directly and indirectly. The stock ended the initial two weeks of the month more than 3% lower, while the Nasdaq climbed less than 2% between the settlement dates. After hitting a 52-week high of $5.53 in March, the stock closed on Thursday at $5.40 a share. The 52-week low of $3.74 was seen last summer.

Short interest at Yahoo totaled more than 63.70 million shares in the middle of May, which was up more than 7% from two weeks earlier. That was the highest level of short interest in at least a year, and it was also 7.2% of the total float. The days to cover grew from around seven to more than eight during the period.

This internet portal pioneer is in the process of being acquired by Verizon. Short sellers watched its stock rise more than 3% during the settlement period and a little more afterward. The most recent closing share price was $55.71, which is up around 44% higher year to date. The Nasdaq is up more than 17% in that time. In the past year, Yahoo shares have traded between $35.05 and $55.94 apiece.

New short interest data are due out later today. That will offer a look at how the short sellers moved in the latter half of May, not only with regards to Sirius and Yahoo, but all the most shorted stocks on the New York Stock Exchange and on the Nasdaq as well.