Twitter has submitted its amended Form S1with the Securities and Exchange Commission, which revealed that the company will be offering 70 million shares in its initial public offering.

The document stated that shares are priced at $17-$20, which will allow it to raise somewhere between $1.4 billion to $1.6 billion, and will bring the company’s value to $11 billion.  Previous rumors had put Twitter’s valuation at $15 billion.

Some may think that Twitter has valued its stock too low, but the microblogging service is just being cautious.  They do not want a repeat of what happened to Facebook – whose stocks were priced at $38 per share, only to trade far lower than that soon after its public debut.

There’s still a chance that Twitter’s share price will go up or down, depending on the reaction of institutional investors in its formal “road show.”  But the main goal here is to not lower the price that what has been proposed.  The “road show” begins today and will last two weeks. After that, Twitter will be able to set its official price.

The SEC filing also showed which directors and executives will be selling their shares. CEO Richard Costolo owns 7,675,239 shares, or 1.6 percent of the company, but will own 1.4 percent after the company’s IPO, valuing his shares at around $140 million if they sell at a median price of $18.50.  Chairman Jack Dorsey owns 23,453,017 shares, or 4.9 percent, and will sell 0.6 percent of these, putting his value at $430 million after the IPO.  Co-founder Evan Williams owns 56,909,847 shares, and will be selling 1.6 percent of the company’s total, putting his value at about $1 billion after the company’s IPO.

“The mission we serve as Twitter, Inc. is to give everyone the power to create and share ideas and information instantly without barriers. Our business and revenue will always follow that mission in ways that improve–and do not detract from–a free and global conversation,” Dorsey said in the filing.

Twitter’s common stock has been approved to appear in the New York Stock Exchange under the ticker TWTR.