Amid the campaign’s final frenzy, there are encouraging signs that Trump’s slow-to-build money operation has matured to presidential caliber, but alarm persists that it may be too late to combat Hillary Clinton’s big-dollar machine, according to a dozen people with ties to Trump’s finance team.

The fundraising quarter that ended Friday has injected sorely needed cash into Trump’s White House hopes, with long-sought donations finally clearing and optimism abound that Trump himself will match his tightening poll numbers with a loosening of his own wallet.

Trump has two families in particular to thank: the Adelsons of Las Vegas and the Ricketts of the Midwest, who are behind the scenes directing major cash — and critically, major credibility — to Trump’s fundraising ambitions. Despite only publicly committing $5 million to what is likely to be the de facto Trump super PAC, Sheldon and Miriam Adelson are pledging at least $25 million to pro-Trump presidential efforts, according to multiple people briefed on their donations. That sum includes giving to nonprofit group that will never be required to disclose his donations.