The ink from Mayor Ed Lee’s signature is barely dry on Supervisor Ross Mirkarimi’s moratorium on stock-option taxes, and now the one company that the legislation will benefit most is talking about going public.

Various sources are reporting that San Francisco-based gaming company Zynga is set to announce its initial public offering Wednesday at $1.5 to $2 billion. Yes that’s billion with a B. The company’s total worth may reach $20 billion.

Before the legislation was signed on June 2, Zynga would have had to pay 1.5 percent of all the compensation its employees earn by exercising their stock options in the company. If you take 1.5 percent of 20 billion, you get $300 million.

But at least Mirkarimi and co-sponsor Board President David Chiu amended the tax break to only apply after a $750,000 threshold was met. So, while San Francisco could be missing out on hundreds of millions of dollars in tax revenue, it won’t come away empty handed.