Earlier quoted context omitted.
so, I trust amazon too (at least the 'shipped and sold by amazon' brand... I consider everything else to be more like ebay) But... I just don't see how amazon would get me away, say, from vanguard. There are already good retail brokerages, and I don't see why I'd want to go through amazon instead of another company.
There are lots of ways, of course: A. Going global: a lot of those "good retail brokers" are US-only. Sometimes it's dumb - I already have an ETrade account & signed all the paperwork including stuff relevant for my foreigner status... But ETrade will only let me trade my employer's stock, nothing else. B. Bundle stuff that others can't match - e.g. Prime C. One account, with good actual security (few appreciate that…
but B? I don't see why I want to bundle my stocks with my television series. And, I'm not sure Amazon has security that is any better than Vanguard.