24/7 Wall St.

Among the most heavily shorted stocks traded on the Nasdaq, the big mover between the May 13 and May 31 settlement dates was Apple. A surge in the number of the iPhone maker’s shares short lifted it back into the top five. Short interest swings in the others were more modest, and largely positive, though biopharmaceutical company MannKind did see a double-digit percentage decline in the most recently period, its second sharp drop in a row.

Note that only two of the most shorted Nasdaq stocks still had more than 100 million shares short by the end of the most recent period.

Sirius XM

The nearly 201.53 million Sirius XM Holdings Inc. (NASDAQ: SIRI) shares short by the end of last month was more than 3% higher than on the previous settlement date, and it was again the highest level of short interest in the past year. Some 11.3% of the company’s float was sold short. At the current average daily volume, it would take less than seven days to cover all short positions.

The Canadian unit of Sirius XM reportedly is going private. The Sirius XM share price ended the two-week period more than 3% higher, though it has retreated somewhat since. The stock ended Thursday at $3.99 a share, within a 52-week trading range of $3.29 to $4.20.

Frontier Communications

The 1% rebound in the previous period, after five periods in a row of shrinking short interest in Frontier Communications Corp. (NASDAQ: FTR), picked up steam, rising another 3% or so to more than 142.86 million shares. That was 12.3% of the telecom’s float, as of the most recent settlement date. The days to cover jumped to more than 11 as the average daily volume sank to a year-to-date low.

UBS sees the industry as vulnerable in a rising rate environment. Shares ended the short interest period down less than 2%, although it was down about 7% at one point. The Nasdaq gained almost 5% in that time. The share price now still is more than 9% higher year to date and closed most recently at $5.12, within a 52-week range of $3.81 to $5.85.
Apple

The number of Apple Inc. (NASDAQ: AAPL) shares short jumped about 79% in the period, in a time when hedge funds were washing their hands of the stock. The nearly 99.70 million shares short at month’s end represent 1.8% of the float. That was handily the highest level of short interest year to date. After the average daily volume dropped off in the period, it would take more than two days to cover all short positions, also a year-to-date high.

Warren Buffett’s Berkshire Hathaway has bought into Apple, however. The share price increased more than 10% between the settlement dates, and it has added on another 2% since then. The stock price was $99.65 per share on Thursday’s close. It has traded in the past year between $89.47 and $132.97.

AMD

By the end of May, Advanced Micro Devices Inc. (NASDAQ: AMD) had more than 91.34 million shares short, which was up from nearly 84.63 million on the previous settlement date. The most recent reading totaled 14.1% of the company’s float. The days to cover dropped to less than four as the average daily volume rose sharply.

AMD named a new chairman earlier in the month. Short sellers watched the share price climb more than 24% during the two weeks. It reached a new 52-week high of $4.71 recently, and closed Thursday at $4.52. The 52-week low of $1.61 was seen last summer.

MannKind

MannKind Corp.’s (NASDAQ: MNKD) short interest, at almost 86.48 million shares most recently, was down about 11% from the prior settlement date. That was the fewest shares short in at least a year, but it was still 26.7% of the total float. The days to cover remained about 15, even as the daily average volume decreased somewhat.

MannKind posted a deeper-than-expected first-quarter net loss earlier in the month. Despite about a 9% gain early on, the stock ended the two weeks up less than 2%. Shares are now about 29% lower year to date to $1.03, still well up from the multiyear low of $0.64 earlier this year. The 52-week high of $7.32 was seen last summer.

Intel

About 78.48 million Intel Corp. (NASDAQ: INTC) shares were sold short as of the most recent settlement date. That was almost 3 million less than at the start of the period, and it totaled 1.7% of the company’s float. The year-to-date high was more than 91 million shares back in March. With the average daily volume still near the year-to-date low, it would take less than four days to cover all short positions.

At least one analyst recommends selling Intel shares. Yet, the share price ended the two weeks more than 5% higher than on the previous settlement date. It has risen about 1% since then and closed at $31.94 on Thursday, still down more than 7% year to date. The stock has changed hands between $24.87 and $35.59 per share in the past year.

And Others

Rounding out the top 10 were Huntington Bancshares Inc. (NASDAQ: HBAN), Novavax Inc. (NASDAQ: NVAX), Micron Technology Inc. (NASDAQ: MU) and BlackBerry Ltd. (NASDAQ: BBRY). The standout among these four was Huntington, with a more than 10% rise in short interest, while the number of shares short in the others dwindled.

Note that NVIDIA Corp. (NASDAQ: NVDA) slipped out of the top 10 in this period, while Marriott International Inc. (NASDAQ: MAR) continued to linger just out of the spotlight.