Pandora Media Inc (NYSE:P) shares surged by nearly 5% today as reports about rising short interest in the streaming music provider came out. Zynga Inc (NASDAQ:ZNGA) stock climbed by 4%, while Groupon Inc (NASDAQ:GRPN), which saw the greatest decrease in short interest last month, rose more than 1%.

Pandora

Groupon’s short interest plunges

According to Benzinga, short interest in Groupon Inc (NASDAQ:GRPN) fell by more than 21% during the month of April, plunging to 54.33 million shares. This is the lowest level it has been at since February. The amount of sold-short shares was approximately 12% of the float. Despite the decline in short interest, the number of days to cover increased to over four.

Analysts believe Groupon Inc (NASDAQ:GRPN) will post flat earnings in both the current and next quarters and also for the full fiscal year. The daily deals giant’s market capitalization is almost $4 billion. On average, analysts surveyed by Thomson / First Call have had a Hold rating on Groupon for the last three months, although the average price target reflects a 35% increase in the current share price.

Pandora Media’s short interest climbs

In the last couple weeks of April, short interest in Pandora Media Inc (NYSE:P) increased to over 15.5 million shares, a 17% increase. The number was a little over 8% of the company’s float and the largest number since February.

Pandora Media Inc (NYSE:P) beat revenue estimates for the most recently completed quarter, although it reported worse-than-expected losses. The streaming radio company’s market capitalization is over $4 billion. Twenty analysts of 31 who were surveyed have a Buy rating or equivalent on Pandora. Seven of them actually have a Strong Buy rating, saying that the stock has lots of room to grow. The average price target reflects a more than 35% premium over the current share price.

Zynga’s short interest surges

Short interest in Zynga Inc (ZNGA) surged, climbing by over 24% in April to approximately 64.72 million shares. That’s approximately 10% of the float and is the largest number of short-sold shares within the last year. The number of days to cover, however, is less than two.

The company’s net losses for the first quarter declined, while revenue beat expectations. Zynga Inc (NASDAQ:ZNGA)’s market cap is approximately $3 billion. The number of analyst Underperform ratings from analysts is higher than the number of Buy ratings, which could play into why short interest has risen so much in such a short amount of time. However, if the stock moves to the average price target, it would have to increase by over 25%.