While Hillary Clinton and her allies have spent almost $100 million on television advertising, Donald Trump has yet to spend a cent, NBC News reports.

Despite raising $82 million in July, according to The New York Times, and lagging behind Clinton in many recent polls, Trump still refuses to buy any air time. Clinton's campaign, by comparison, has spent over $52 million on general-election TV ads so far.

"First of all, I don't even know why I need so much money," Trump said about his fundraising at a campaign rally a month ago, according to The Washington Post. "You know, I go around, I make speeches. I talk to reporters. I don't even need commercials, if you want to know the truth. Why do I need these commercials?"

Last week Trump tweeted an ad attacking Clinton on her leadership, but hasn't released any details about the money behind the ad, or whether it would run on TV, The Los Angeles Times reports.

Pro-Trump groups have shelled out about $8 million for ads on their candidate's behalf, but that trails Clinton's supporters by $29 million. Even third-party candidates Gary Johnson, the Libertarian nominee, and the Green Party's Jill Stein have spent more on ads than Trump.

Trump "cannot survive the professionalized deconstruction that Hillary is doing every day," according to GOP ad designer Will Ritter, who told the Associated Press, "I'd love to know what they're waiting for."