@NC-RetiredThere's a guy called Mackey Chandler. He's active at the periphery of the Baen authors' group, but AFAIK never published by them. Instead, he does his own thing on the Rainforest site and their Limitless Firewood program. He has two series, which he is in the process of merging together.
In the earlier of the two series, "April", he describes setting up banks and working with the terrestrial banking system (from the POV of people living on a space station). His first system involves a commodity money coinage, which eventually gets extended to a representative money system due to the need for small fractions.
At some point, he adds in characters from the far east, and introduces some of the concepts of eastern banking - Hawala. This gets explored in terms of there being an extant, non-western banking system, and what services and expectations there are.
(The April series is very much a libertarian-struggle story. There are even points where the characters acknowledge some of the holes. So if you are into e.g. Michael Z Williamson, you might like the story. Or, if you can't handle that kind of thing, you know to stay away.)
Interestingly, I read the April series and then I was able to recognize that one of the Incomplete stories here on SOL, involving Genies, was hinting around at Hawala banking. I don't believe it was ever spelled out, but looking back it seems obvious. Here we go: https://storiesonline.net/s/45518/the-djinni-and-the-lamps "The Djinni and the Lamps" by exalphageek.
IIRC, the author announced they were not going to be able to finish the story, because ... reasons. ISTR is was because the story was a favorable story about the middle east, and 9/11 had happened, or something. I pinged them a few years later and got the impression they were no longer in a place where they could continue the story. It's a shame, since the story seemed *really* promising. I wish they had gone ahead and finished the story - maybe it would have been flamed, but it might have shortened the whole sandbox thing by a picosecond or two.
Also, "Nick, High School" by SmokinDriver features a kid that invents automated trading as part of his side hustle: https://storiesonline.net/s/76726/nick-high-school ; and "Climbing the Ladder" (https://storiesonline.net/s/25751/climbing-the-ladder) by Michael Loucks features a kid who starts working at an investment firm. And "A Fresh Start" (https://storiesonline.net/s/68384/a-fresh-start) by rlfj features both a magic lamp and venture capital (but not very much of either one).
Finally, there once was an author called ... gwresearch, I think. They had a story called "K2" which I think was posted to SOL. Gone now, but available from author "Geoff Wolak" on the Rainforest site. The story involves a fellow who "inherits" a controlling interest in a bank. It quickly stops being about banking and starts being a Nazi-gold "men's adventure" thriller with WWII bunkers and stuff. But they do spend at least one day visiting a bank!