They are the same model. They both buy stuff, do some stuff and then re-sell the same stuff but with the modifications they made.

In the case of a trading shop, the stuff they do is playing the market liquidity, collecting interest, arbitrage, etc...

Sure there are some evil ones, but other businesses have those too.

Yes, this is pretty much it. As I said in another comment, Jane Street does not have customers for whom they provide goods or services. Their primary business model is using the company's own money for investments, and that's a business model that I don't love.

Considering how many high finance shops live off of gambling with other peoples' money, I find the intellectual honesty of a company doing it on their own dime ... refreshing.

Company spends its own money to make money for itself?

Not exploiting teenagers in some 3rd world country?

Not gambling with your pension?

Not manipulating some physical commodity like oil?

What’s the problem here?

> Not exploiting teenagers in some 3rd world country?

> Not gambling with your pension?

> Not manipulating some physical commodity like oil?

There is no reason to believe #1 and #3 aren't true, and I should very much suspect they are. #2 is not possible as far as I can tell, I agree there.

> - We use cash to rent a building, order pallets of inventory, and sell that inventory locally to walk-in customers.

> - We use cash to buy shares, hold onto them for a bit, and sell those same shares and make money off the spread.

Those two sound like pretty much the same thing.

Indeed, but not like the first one.