Billionaire Michael Bloomberg is preparing a $500 million fund from his own money to block a potential second term in the White House for Donald Trump, Politico reports, whether he runs for president or not. Bloomberg is still mulling a presidential run—if he goes ahead, that money will fire his campaign through the 2020 primary season, with more cash reportedly being available if it’s needed. If he doesn’t run, the money will reportedly fund a data-heavy campaign designed to “operate as a shadow political party for the eventual Democratic nominee,” according to Politico. “Mike spent $100 million in his last New York City election. And you can do the math as you think more broadly, but New York City is 3 percent of the national population,” said Kevin Sheekey, a top Bloomberg adviser. “I’m not suggesting it’s straight math. But I’m suggesting that when Mike Bloomberg is committed to making a difference and seeing something though, generally speaking he’s pretty unabashed in doing so.” Bloomberg said Friday that he’ll make a decision on whether to run in the next three weeks.