Best strategy: Don't sell unless absolutely necessary.
Buy whenever possible and hold.
Resist the temptation to waste your bitcoins by buying fiat currencies just because the price went up. Be strong.
Do not deviate.
No one's going to sell to leave the money to rot in a bank account, unless they have some sort of condition.
I'm sure many here have areas of their life that they are looking to progress and are exceedingly tired of being chained to this whipsawing headfuck. I sure as shit am. I'd never be fully out of the game but I am extremely keen to not be so deep into it.
When the opportunity arises to exit enough to no longer have to care anywhere near as much it's being grabbed with both hands. Around half should do it.
It is a ratio thing.
Always be prepared to sell some, but not all.
Also when people say numbers like :
10,000 ----------- been there done that
20,000 ----------- been there done that
50,000 ----------- to move to this number by 2021 means 922,339,050,000 or 922 billion
the world's money supply is easily able to achieve bumping btc to 50,000 or 922 billion by the years end
the world has well over 49,220 billion in wealth
so pushing btc to 50,000 by years end is not that hard to do.
So the upside if you have 3 coins right now is 150,000 by 2021 is possible.
If your coins cost you 3,900 x 3 = 11,700
do your math and figure what to sell.
If you want to be highest risk hold it all risking 11,700 for a possible 150,000
If you want to be lowest risk sell it all. you get about 33,000 - 11,700 = 21,300 profit a certain win.
If you are sane and want to do what you said in your post
you sell 1.1 coins gives you 12100 you invested 11,700. you are up 400 usd.
and you have 1.9 coins in hand.
Set a price point for next sell say 20,000
do ratios the upside is the 1.9 could go to 95,000
at 20,000 if you sell .4. you get 8,000
and still have 1.5 coins.
You can alter the numbers since I do not know your cost basis or your coin wealth. But it is the 50-50 game or 60-40 game or 70-30 game I am playing.