[throwaway2037]

    > live securities prices

This is probably impossible in 2025. Many stock exchanges now make more money from selling data feeds than trading fees. It is a little bit crazy. The best that you can hope for is a delayed feed, or last closes.

[yesimahuman]

That's the best part about VTSAX and chill: you only ever have last closes. Really though this does not need to be real time at all, just recent enough to save me toil

[throwaway2037]

I much prefer VOO: Vanguard S&P 500 ETF. Tight bid ask spread, good size, and crazy low fees that continue to drop.

[fullstackchris]

This is incorrect. Almost all brokers nowadays allow for OAuth connections where you can stream any data you'd see in your broker platform to any consuming web application (given the consuming web application does all the paperwork, dev work, and so on)

[throwaway2037]

    > Almost all brokers

That is a mighty broad brush. I can confidently say that this is untrue for many brokers in continental Europe and North Asia. US brokers? If yes, can you provide some examples?

[immibis]

(with a contractual obligation to never share the data with anyone else or they'll sue you for all you're worth)