My only comment re selling ( or buying for that matter), never buy a stock without without making an exit strategy.
It can be a timeframe, stop loss, a particular % or a number.
I kinda follow the timeframe option as I always seem to go long.
Regardless of what exit strategy you or I use, we all have to re-evaluate our commitment to our first plan, regularly.
Good luck with all your plans, may they bare fruit.
Ps
I've followed the Mus story a bit but not enough to comment on where it may end up, only the future people know that.