By James Clayton
BBC North America technology reporter
Donald Trump loves Twitter.
In 2017, he said he wouldn't have become president without it.
"Twitter is a wonderful thing for me, because I get the word out… I might not be here talking to you right now as president if I didn't have an honest way of getting the word out," he said.
After Twitter's new owner Elon Musk reversed Mr Trump's permanent suspension, you might have thought the former president would jump at the chance to come back. But so far, he hasn't taken up that offer.
Well, only Donald Trump knows the answer to that question for sure.
But what we do know is he has a lot of money to lose from tweeting.
"The simplest explanation is the most likely - it's about money," says Josh Tucker, professor of politics at New York University (NYU).
After Donald Trump was kicked off Twitter, he created his own social media platform called Truth Social - that looks an awful lot like Twitter.
To understand the financial bind Donald Trump is in, you have to understand the complex nature of Truth Social's business set up.
Last year, the private company that owns Truth Social, Trump Media & Technology Group (TMTG), announced its intention to merge with a shell company trading on the stock exchange called Digital World Acquisition Corp (DWAC).
DWAC is what's known as a Special Purpose Acquisition Company (Spac). Spacs are hyped as a way to speed up the often slow process of taking a private company public. In simple terms, it means merging a company that isn't on a stock exchange with one that is.
Both TMTG and DWAC have agreed to merge, though the deal has not yet been completed. But that hasn't stopped investors piling money into DWAC - all of them speculating that the deal will go through. The shell company is currently valued at more than $800m (£665m).
Considering DWAC would only be acquiring about a quarter of TMTG, Mr Trump's newly merged company would be worth at least $3-4bn, says Michael Ohlrogge, an academic specialising in Spacs.
"He would own the vast majority. He would own probably 70 or 80% of it."
If it all goes through, it would make this business venture one of the most successful of Donald Trump's career.
But the key to keeping stock value high is making sure that the former president stays on Truth Social - and exclusively so.
It's hard to see what Truth Social has going for it without Donald Trump. The social media company was created by him. Why should even his supporters use the platform if he is posting elsewhere?
Truth Social is already struggling to attract users. Analytics firm Similar Web estimates the platform had eight million site visits in September 2022 - down from 11.5 million in July. For a social media company, that is tiny.
Similar Web estimates that Twitter had nine billion site visits in September.
If Donald Trump were to stop posting, or do it elsewhere, he could potentially tank the share price of DWAC, wiping hundreds of millions of dollars off its value.
So important was Donald Trump's exclusivity with Truth Social to the proposed merger with DWAC, that a legal provision was placed in the agreement.
It states that "President Trump is generally obligated to make any social media post on Truth Social and may not make the same post on another social media site for 6 hours."
It means that not only could Donald Trump lose a lot of money by using Twitter (by spooking investors) but he could also get sued.
"It's hard to say for sure who would win, but it wouldn't be a completely crazy suit to try to bring," says Ohlrogge.
It means Donald Trump is now in a quandary. He might want to go back to Twitter. But he is financially - not to mention legally - incentivised not to.
There are, however, other factors at play that could lead to him tweeting once more.
For starters, DWAC's share price has behaved in very strange ways recently.
Rather than it simply being a place where people can de facto invest in Truth Social, people have been purchasing DWA shares as a way of investing in the former president himself.
"It's a meme stock," says Michael Klausner, Professor of Law at Stanford University. Meme stocks are companies that have lots of small investors who are online or social media followers, who can drive the share price up and down.
Klausner says many who have invested in DWAC are Mr Trump's own supporters.
"They think that Trump's name attached to something is going to be valuable," he says.
It means DWAC's share price goes up when Donald Trump's fortunes are on the rise, and down when they are taking a turn for the worse.
On Monday 7 November, it surged after reports emerged that he planned to run for president in 2024. But nine days later, when he finally confirmed the news in a speech that was criticised as "low energy" - the stock price fell.
The theory here is that although DWAC is merging with Truth Social, what it's really doing is giving Donald Trump an opportunity to float himself - his personal brand - on the stock exchange. If that is the case, it wouldn't matter so much if Mr Trump were to stop using Truth Social - as the social media company is only a proxy for the man himself.
For Josh Tucker from NYU, the situation raises interesting moral questions.
"I have never personally heard of something like this before - that there is a large amount of money tracking what seems to be the political fortunes of a politician."
He warns that a politician might go on to make decisions based not on what is good for their political aspirations, but their financial ones instead.
"If you're a Republican, you might want your Republican nominee to use the media to the best of their ability," he says.
Tucker argues that if Republicans were to elect Donald Trump as their presidential nominee, they would expect him to utilise wider social media in campaigning - rather than just limiting himself to one platform for financial gain.
But Donald Trump may have anticipated this problem. Buried in the merger agreement there is another provision that allows him to use other social media platforms for "political messaging".
It may be a "loophole", says Klausner, that would allow Trump to tweet without breaching the contract.
Not only that, but Mr Trump is only bound by the agreement to post exclusively on Truth Social until July 2023, says Ohlrogge.
"My reading is after that point [legally] he'd be able post directly on Twitter, without posting first on Truth Social," he says.
There is another reason to think Donald Trump might come back onto Twitter. The merger itself is currently under Federal investigation.
The deal could still fall through, at which point Donald Trump's legal commitment to post exclusively on Truth Social would also be ripped up.
Mr Trump might lose money, but it would open the door still wider for a Twitter return.
As with many of Mr Trump's financial affairs, it's complicated. And Donald Trump is not a person who is easy to predict.
But what we do know is that were he to stick with Truth Social exclusively, and complete the Spac merger, he would likely earn a small fortune.
It's hard to see how that's not a major factor in his thinking. Will that calculation change as we get closer to an election?
It may well do. But for now, Mr Trump says he's staying put.