What do the terms Sell and Buy of a stock mean

External question — Personal Finance Stack Exchange Author: Hassan Original post: https://money.stackexchange.com/questions/128050 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. What is meaning of SELL and BUY of a stock, commodity, or ETF? When I choose any specific position of SELL or BUY , why do I have an immediate loss/profit? For an instance I am doing paper trading on a platform and choose/bought SELL position of Silver at 18.70 $ while same time there is .05 $ difference in BUY position but I was in lose, so it was bit confusing for me. After few days SELL position value increase to 20.00 $ and I was in lose of 250 $ which is really weird for a newbie like me