Trump Media & Technology Group stock (DJT) extended gains by another 18% on Tuesday — its longest rally since June — after shares closed up more than 10% the day prior.

The moves come as investors assess Democratic nominee and current Vice President Kamala Harris's recent media appearances, along with a surprise cameo by Elon Musk at Donald Trump's rally in Butler, Pa., over the weekend. It was the same location where the former president survived an assassination attempt in July.

Tech billionaire Musk, who serves as the CEO of Tesla (TSLA) and SpaceX and also owns social media platform X (formerly Twitter), has been outspoken about his support of Trump ahead of next month's election. Trump has even said he would consider a Cabinet position for Musk but that the businessman likely would not be able to serve "with all the things he's got going on."

At Saturday's rally, Musk told the crowd that Trump is the only candidate who can "preserve democracy in America," adding this will be "the last election" if Trump does not win.

The former president remains in a deadlocked race against Harris, who just embarked on a flurry of media appearances in an attempt to solidify recent momentum in the polls.

Harris appeared on an episode of "Call Her Daddy," a popular podcast catered toward Generation Z, along with a sit-down interview for CBS' "60 Minutes."

In the one-on-one interview with CBS correspondent Bill Whitaker, Harris defended her proposals on the economy and immigration but was pressed on how she would fund some of these efforts.

Trump backed out of an interview with the program last week after previously agreeing to the sit down, according to the network.

Trump maintains a roughly 60% interest in DJT. At current levels of around $22 a share, Trump Media boasts a market cap of about $4.4 billion, giving the former president a stake worth around $2.6 billion. Right after the company's public debut, Trump's stake was worth just over $4.5 billion.

Trump Media went public on the Nasdaq in late March after merging with special purpose acquisition company Digital World Acquisition Corp. But the stock has been on a bumpy ride since, with shares oscillating between highs and lows as the moves have typically been tied to a volatile news cycle.

Last month, the stock traded at its lowest level since the company's debut following the expiration of its highly publicized lockup period.

Stakeholders, including the former president, were subject to a six-month lockup period before being able to sell or transfer shares. That lockup period expired on Sept. 19, although Trump said at the time that he would not sell his stake.