Let's say I don't want to buy BTC at its present value. But, if I wait until BTC falls in price, and want to buy it then, it would take 7 days for me to receive my BTC.

I wish I could load USD onto a site, and then when I feel like buying BTC I can do it immediately. Also, I don't want to rush off to 7-11 whenever I have the desire to buy some BTC. I want to do it from my computer inside a house/office.

Step 1: Load USD onto xyz.com
Step 2: Buy/Sell BTC whenever I want

Whichever company can do this, will make a fortune in future.

If there is a company like this, please let me know.

Thanks!