"I don't see that relationship lasting longer than 6 months," said Peter Brown, Managing Director of Baggot Investment Partners in Dublin.
The market analyst is not alone.
Before Donald Trump took office last Monday, markets were preparing for shifts across various sectors, including stocks, forex and cryptocurrencies.
They were also braced for the Musk factor.
President Trump and the X CEO have remained seemingly inseparable. Musk has been a constant presence as Trump charted out his second administration. He has sat in on calls with world leaders, and joined Trump and his family members for meals at Mar-a-Lago.
Most notably, he enjoyed a prime position at the inauguration at the State Capitol, along with other 'tech bros'.
But is the bromance a great alliance that will benefit the US economy, or a disaster waiting to happen?
"The markets are betting at around 6 months for these two personalities to collide and fall out," Mr Brown said. "The markets do not believe there is room for both these personalities long term."
President Trump and Elon Musk want to make the federal government leaner and more efficient by reviewing its budget and operations from top to bottom.
Musk has warned that his goals include cutting at least $2 trillion in federal spending, partly by axing inefficient federal workers.
"The issue I think with Musk is very, very simple," Mr Brown explained. "He has got this Department of Government Efficiency; if he's not able to go in and blanket fire people like he does in X, and anywhere else he's involved, he's going to get frustrated very quickly.
"He can't do that without changes in Congress legislation, which is not going to happen. I don't see that relationship lasting longer than 6 months."
The market analyst is not alone.
After a honeymoon period, other market experts predict that the alliance between the US President and Elon Musk will unravel in 2025.
Global US technology market analyst firm, Canalys, predicts Trump and Musk will fall out over China, if the president implements his promse to introduce 60% tariffs on all Chinese goods.
He shied away from doing so in his first few days in office, which steadied markets.
Musk is reliant on China as a market for Tesla, and it is a source of batteries and other minerals for the electric vehicle-maker. A blow to China could put Tesla's ability to manufacture self-driving vehicles at risk.
Tesla shares have gained 98% in the past 12 months, and most of the gain came after the presidential election.
The company is one of the most valuable in the world, with a market valuation of $1.24 trillion. Musk has said he believes Tesla can cross a $4 trillion valuation in the future. If that is to be achieved, the company's relationship with China is key.
He also sees a future driven by AI and robotics, proposing advancements in autonomous vehicles and humanoid robots to reshape industries.
These technologies could face fewer regulatory hurdles if Trump delivers pro-tech policies under Musk's watchful eye.
In his inaugural address, President Trump promised to plant an American flag on Mars. The cameras turned to a smiling Elon Musk who waved his hands in celebration.
Musk has ambitions for Mars colonisation through his space technology firm, SpaceX continue, with support from a Trump administration favouring deregulation.
This could accelerate missions under NASA's Artemis program, which SpaceX supports.
Musk is also a proponent of cryptocurrency, even naming the Department of Government Efficiency, which he heads, after the meme-based dogecoin.
The Trumps launched their own meme coins the weekend before inauguration day.
The then President-elect took to social media platform Truth to say, "My NEW Official Trump Meme is HERE! It's time to celebrate everything we stand for: WINNING!"
The incoming First Lady Melania Trump followed suit. Both coins have risen but have seen volatile trade.
Bitcoin has also bounced. Its price is rallying almost 4% this week and was hovering above $105,000 on Friday after hitting a new all-time high of $109,588 on inauguration day.
Cryptocurrency investors are banking on Trump following through on his crypto policy pledges while in office.
Lenny McLoughlin of Irish Life Investment Managers said the first one hundred days of any administration is crucial to setting the tone for what's to come.
President Trump certainly did that on day one.
The ILIM Investment Strategist forecasts positive economic growth in the US; "close to double digit, 10 - 12% maybe, in the States in terms of equity performance".
"You will have volatility in markets," Mr McLoughlin said. "Again our base case is, growth will remain positive."
He said Trump has a history of chaotic policy announcements. "I think that's one thing we can look forward to, and I think with that, you will see more volatility with that in 2025 than in 2024.
"With that you need to have a diversified portfolio."
Time will tell what the next four years of the Trump presidency will mean for markets, but in the short term, at least one investor is benefiting in a big way from the new administration: Elon Musk.
The X and Tesla CEO could fall out of favour with President Trump.
If things don’t go as well as they appear to be going now, will it impact Musk's portfolio? Doubtful.
Ultimately, the value of Musk’s companies will be able to weather any future volatility or shifting political winds.
But have the markets priced in a break-up of this bromance?
