After starting off the week at an all-time low, Zynga’s stock is beginning to rise again while Facebook’s initial public offering approaches.

The stock closed today at $8.22 a share, down from its opening at $8.75 but still notably higher than where its price was at the beginning of the week. Since Monday, Zynga’s shares have opened above their closing point from the previous day. The stock could be improving as Facebook’s Friday IPO draws near. The social network will likely be valued at over $100 billion with a stock price between $34 and $38 a share.

Facebook recently revealed in an S-1 amendment that Zynga was responsible for 15 percent of its 2011 income. When Facebook’s February S-1 showed 12 percent of its income came from Zynga, the developer’s stock rocketed up to over $14 a share before starting to fall back to previous levels. If the social network’s IPO is as big a success as many believe it will be, Zynga’s stock will likely see an even more dramatic share price increase.

Zynga’s stock still hasn’t taken off like many investors hoped it would when it began trading in December; shares didn’t return to their original price until late January. The stock managed to stay above $10 for February and March, but began a significant slide in mid-April, especially after the company’s Q1 earnings call on April 26. Although the company reported record bookings, it also reported a net loss of $85.4 million and shares dropped from $9.50 to $8.52 the next day. Shares continued to drop over the past two weeks, hitting an all-time low of $7.45 last Friday.

This post originally appeared on our sister site, Inside Social Games.