It's best to keep it private if you're a Bitcoin investor, and don't tell anyone how many Bitcoins you have. When someone else hears about your bitcoins, it can be seen that they can try to harm you in many ways. Because you own bitcoins, you own at least a good chunk of money. It will try to get away from you and not hesitate to harm you, so it is best always to maintain secrecy.
Many of the times when people brag about what they own or assets they have, it might be under the influence of alcohol or drugs which makes them so loose that they don't even know how high their voice is and don't even care for the kind of people sitting in and listening.
It's good not to brag in general, not only because one has a Bitcoin investment but because it potentially put one in harms way.
When it comes to crypto currency and Bitcoin in particular, it's best to keep it a secret as it is a private privilege for those who own it and intend to hold it for a long time and mostly because of the scare of government policies and ban and arrest for citizens who live in regions where it isn't yet a recognized legal tender and also because of terrorism and kidnapping and even possible theft from those close by.
Everything that involves your financial asset, it should be kept privately. No one would be happy of your own success but just only yourself, so as much as possible, don’t do things that will make other people develop envy on you, otherwise you will definitely find yourself in a very dangerous situation.
Yes, in general, just try to live low key. Don’t tell other people about your success and your rewards, majority of them will only see you bragging, most especially when it comes to bitcoin, it’s like you are attracting silent hackers and scammers that are waiting in the corner targeting some victims.