you can open an acct w/ either fund family like DWS INVESTMENT or stock broker as TDAmeritrade, E*Trade, Scotte, etc..

same fund, of course, same performance no matter where it sits. hence, 是一回事.

however, there are a lot of uncommon issues like

- fees, e.g. is it NTF (no-transaction-fee) funds?

- cut off time to buy or sell;

- short term redemption fee;

and so on...

whoever you belong to, fund family or broker, you need to understand its rules, i.e. Prospectus, before investing.

hope this helps. and here is your homework.

let's say you want to buy KTCSX, can you figure out what the difference is btw buying directly from DWS or from TDAmeritrade indirectly?

good luck!