So I own $1000 in bitcoin but I want to invest the remaining amount to accumulate a whole bitcoin. The prices fluctuates every second so how can I do this on coinbase? I believe this is called a market buy order and I've looked at the steps on how to do this but I think they're outdated or wrong.
Since you are new and want to know more about this things best to move this topic to beginners help sections and possibly you will get the correct output for your questions since there are more veterans users who help newbie users for there questions
https://bitcointalk.org/index.php?board=39.0And since you want to buy bitcoins then make sure that you are ready to buy at this rate since as you said the price is flactuating and might you will lose aswell get panic if certain falls happen but if you are a risk taker and willing to hold then look at the current price and initiate/execute your buy order and it will be filled.