Oracle has leapfrogged Microsoft as the most likely buyer of TikTok's U.S. operations, according to multiple sources familiar with the process. But the situation remains very fluid, including the possibility of no deal at all.

Key questions: What exactly is for sale, and could President Trump accept a deal in which some of TikTok's core technology remains with Chinese parent company ByteDance?

Between the lines: Original deal talks involved all of TikTok's operations, including its underlying algorithm, in the U.S., Canada, Australia, and New Zealand.

• New Chinese tech export rules have complicated matters, with the South China Morning Post reporting on Sunday that ByteDance "will not sell or transfer the algorithm." Axios has not been able to confirm that development.
• One source says that ByteDance has now limited talks to TikTok's U.S. assets, saying the original quartet was an artifact of how ByteDance structured the business, not based on strategy or government pressures.

Oracle is more likely than Microsoft to accept a deal in which it serves more as a cloud services provider than as a traditional parent company.

• Oracle also is working with certain existing ByteDance shareholders, which could make ByteDance and Beijing feel more confident that they are maintaining a level of control.
• It also has some very close ties to President Trump, who would need to sign off on any deal. Oracle executive chairman Larry Ellison earlier this year held a fundraiser for Trump, and Oracle CEO Safra Catz served on Trump's 2016 transition team.
• As a caveat, Microsoft still has much deeper pockets and more consumer tech expertise than does Oracle. If ByteDance opts for a clean break, Microsoft remains its best option.

Timing: President Trump originally said that a deal must be reached by Sept. 15, but his executive order gave ByteDance until Sept. 20. On Friday, he said the deadline will not be extended.

• TikTok continues to litigate its objection to Trump's executive order, and likely would ask for an emergency injunction were the President to institute a ban.

Go deeper:Inside TikTok's killer algorithm