This is what everyone knows. But to do this is not easy. You need to have the knowledge and grasp the psychology of the investor you can make a lot of profits.
The current market price of Bitcoin has declined today and I do not think so to sell in the current market because it may hurt you or you may have a small profit here but this is something out of mind if you sell for small profit. You can think for a decision to buy more at this stage as Bitcoin has shown its availability on low price and you will get it cheap as compared to its own average price it is in its cheaper stage.
Most of the traders are waiting for high market to sell out for maximum profit and they are waiting for long time as the market price took a long time to recover but has not recovered yet. However we can wait some more time for we are here to get huge profit and this will happen once in this long term trading with the Bitcoin. This market will shift into high value market only if the demand rate increases in the upcoming days.