Career progression vs Uncertainty in this Job Market

Hello everyone, f25 here. A little conflicted between 2 options and would like some advice from the older folks here.

Background:
I graduated last year with a science degree where I landed my first job in a BB middle office before moving into my current role as a Business Development in the credit lending space at a Fintech firm.

The intention to do an industry switch from what I was studying was purely out of an interest. From the time I set sight that I wanted to pivot into the business/finance, one of my goal was to get close to the ‘front office space’.

Context:
I was still applying to graduate program for sales/trading/brokerage/etc while being on probation at my current firm. My thought process was if I didn’t managed to land an offer, I will stay for a year before deciding again.

Unexpectedly, I managed to land a graduate program in a brokerage firm and took it. The starting date is at the end of Q2, thus I have yet to resign.

Dilemma:
So, as the months passed, I grew to enjoy my current team environment, people and the job itself. Naturally, I started to question whether moving into the new role would be the ‘right’ choice.

The opportunity cost is giving up stability and comfort for a higher compensation (6% higher than current and will be revised again once converted) and better career progression, but with the risk of no conversion (the programme is 6 mths).

Just would like to hear opinions and thoughts to those who’re in the industry or older peers :)

Thank you very much in advance for your inputs!!