What: Shares of iDreamSky Technology Ltd. (NASDAQ: DSKY) were down 10.7% as of 2:50 p.m.  Monday after the mobile game specialist announced it had received a preliminary non-binding proposal to acquire the company.

So what: Specifically, iDreamSky Chairman and CEO Michael Xiangyu Chen has offered to purchase all outstanding shares not already owned by him or his affiliates for $14 in cash per American depositary share. Shares of iDreamSky Technology closed Friday at $14.57 per share, or 4% higher than Chen's offer. As it stands, Chen and his affiliates already own 22.1% of all outstanding iDreamSky shares, representing roughly 40.6% of the company's total voting power.

Now what: To be fair, iDreamSky stock is still up 55% over the past month even after today's drop, and the offer represents a 24.5% premium to the stock's volume-weighted average closing price during the last 30 days. iDreamSky also notes it has made no final decisions, and has formed a special committee of independent directors to consider the proposal.

On one hand, if the company decides to accept the offer, that leaves roughly 8% upside from the stock's current level around $13 per share. On the other hand, given iDreamSky's massive gains over the past month and the possibility of this acquisition falling through, I wouldn't blame shareholders for taking at least some of their quick profits off the table today.