I know this is a very basic question, but I am just curious about all this exchange stuff and I'm new to this.. so here goes
If I trade at a bitcoin marketplace (exchange) lets say Kraken, Bitstamp or wherever.. and I for example buy 100$ worth of Bitcoin.
The next day Bitcoin falls and I go negative eg. -7,8
What does this mean? a) did I just loose 100$ and have to pay this extra 7,8 to get back to 0,0? b) or did I just loose 100$ because the price fell but am still the owner of that 0,0001 BTC and I wait a couple of days so the value goes up again and I go positive, or sell everything and accept the fact that i blew 100$?
Which one is it?