While investing in stock, commodity, bitcoin, alt-coins, forex etc one could go with
1: Lump sum purchase of big amount. Purchase bitcoin in quantity when price is comparatively low that previous weeks. Purchase date, timing could be adjusted as per individual suiting.
2: Other way is to follow the SIP that systematic investment plan. This SIP will purchase bitcoin worth $100 or whatever predefined amount. So monthly purchase of fifty dollars or convenient one worth bitcoins will be purchased. Irrespective of price of bitcoin at that time.
What do you think which one works best in long term? and which one works in short term? Which will earn better profit?
I'll go with option 2 for long term. Option 1 is a bit tricky, with bitcoin you can't pretty much pinpoint or target a certain timing in pricing. Also, take note of some potential dips that can be a great source of profit. Buy at a low price, hodl for a while and sell.