Wow this is like a flashback to my own experiments in Excel, prior to going full mad-scientist for the past 6 months and creating a web app for FI/FIRE planning called ProjectiFi:
I had been using similar functions in parts of my spreadsheet, but as I kept adding more and more nuance and flexibility to the life planning and projection aspects, eventually the formulas just reached such a critical mass that the whole spreadsheet got really painful to maintain. If you feel like kicking the tires on ProjectiFi, I'd be curious to hear your thoughts -- I've been working hard to make everything that had become unwieldy and difficult in Excel for FI planning and experimentation feel more intuitive and straightforward.
Are you planning to add a self-hosted option? My one thing about all these finance SaaS is that I'm sure part of their business model is selling your data, even if anonymised. I'd be happy to pay a one-off fee and self-host it or something.
Selling data is not part of mine. In fact, once the page loads you should be able to turn off your internet connection and have all the planning/simulation features still work. Everything stays client-side by default, the only way plan data is ever transmitted anywhere is if you upgrade to Premium and then choose to enable cloud synchronization (which is one of 3 different data persistence methods).
Have you gotten much traction on the subscriptions? I made some financial simulations for my own use and was thinking about ways to monetize, but I dismissed subscriptions as I didn't feel there would be a big market. I'd love to be wrong about that.
Anyway, I don't plan to actually make a product out of mine, but if you're interested in speeding up Monte Carlo financial simulation by literally a million times, let me know :)
It does seem a bit niche, but there's been modest traction so far. And sure, I'd be curious to hear how your Monte Carlo implementation might differ. Feel free to reach out on email/discord if you'd like to chat more.
> And sure, I'd be curious to hear how your Monte Carlo implementation might differ.
Excel is just too slow/not the right tool for MC (or most serious statistics). From my experience with mcmc, compiled languages come in pretty handy to speed up any loop that just can't be vectorized with some linear algebra. So I'd use any tool I'm comfortable with to set up the simulation but delegate the hardcore simulation loops to something like c++.
Agreed on Excel not being a suitable tool for MC; that's one of the many things that pushed me in the direction of building ProjectiFi. Within ProjectiFi, I'm sure there are some things that could be done to speed them up further (e.g. offloading them to a backend where they can run faster), but there could also be some trade-offs with that -- for one, it would violate the "everything stays client-side by default" principle mentioned in another comment.
> I'm sure there are some things that could be done to speed them up further (e.g. offloading them to a backend where they can run faster), but there could also be some trade-offs with that -- for one, it would violate the "everything stays client-side by default" principle
I guess it's just me who hasn't yet seen any serious mc simulation running on a client I guess :/
The way I see this done whenever it runs fast is using c/c++/java. Another important thing with statistics is the mathematical validity of your results, regardless of whether they look right. For validation, most literature I come across uses c/c++/r.
Hey, could you add support for cryptocurrency in investments? So that I could enter how much I have in cryptocurrency instead of $USD, and it would automatically calculate it to $.
Wouldn't that be a real crapshoot anyway, if you're thinking in the timeframes relevant for financial independence? Surely you're not expecting your crypto portfolio to predictably appreciate by 6-8% per year over a 10 year timeframe with large variance.
The potential for going much higher and going down by 90% is in a different league.
For now I tend to agree with marvin here, but I may add something for this eventually. If you already know of some good APIs for grabbing the latest conversion rates, let me know. I want ProjectiFi to feel like it can quickly model most of your what-if scenarios, so support for different asset classes might make sense here, along with customizable growth rates over time (e.g. perhaps the same kind of interactive plot like the stock/bond allocation widget but for playing around with different potential crypto growth rates or something).
Do you mean the animation should be faster when you open a new one? If so, good to know -- that'll be a simple tweak. I'm sure I should put more effort into the landing page overall... the reality is that so far I've spent nearly all my time trying to make the core app robust but intuitive.
In my opinion, the countdown bar (not sure until what it is counting down) is the anxiety inducing part. I’m trying to read, but my eyes keep skipping to the bar to see if I have enough time left.
https://projectifi.io/
I had been using similar functions in parts of my spreadsheet, but as I kept adding more and more nuance and flexibility to the life planning and projection aspects, eventually the formulas just reached such a critical mass that the whole spreadsheet got really painful to maintain. If you feel like kicking the tires on ProjectiFi, I'd be curious to hear your thoughts -- I've been working hard to make everything that had become unwieldy and difficult in Excel for FI planning and experimentation feel more intuitive and straightforward.