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 I believe this is called a market buy order and I've looked at the steps on how to do this but I think they're outdated or wrong.
If your using coinbase theres a spread on top of the actual price, this additional cost insures instant settlement for buyers or sellers, its instant. but If you didnt have the spread you would put an order In for the highest buy price and it might take a couple seconds to clear or it could take minutes it just depends on if someone places a buy order for cheaper than yours.