Talking about the BTC to USD rates.
Because localbitcoins traders knows that bitcoin price will increase in future. Therefore, they buy and sell bitcoin which is more than see in the price chart.
This is why localbitcoins trading is always top than the other trading sites. I personally sell the bitcoin whenever I need and price is also higher than Google rate whenever I check.
This is the dumbest explanation in this thread.
And the rest of the world is trading because they think Bitcoin is shit and will go down soon, but people on Localbitcoins are different, they are the believers
I think the real reason is the premium prices on transactions in person and that this market is unique because it's harder to manipulate. Nobody crashes the price on localbitcoins, so the price is more stable and also reacts to changes in value much slower.