The short answer is create a profile with cryptocurrencies experience or even just getting started into cryptocurrencies, you will get daily invite from people whom are also into this same field.
For me I do know a bit about cryptocurrencies especially bitcoin, I was among one of the daily adopter started mining bitcoin with a laptop that earned me at least 1-10 bitcoin per day, but then not so smart, I sold all of my bitcoin when the price hit $100. That’s right, I sold all my bitcoin when the price was $100 each. Off course I feel awful now price stabilized at $3000 or so, although it did reach to $20000 ($20k).
Anyhow, with some cryptocurrencies experiences updated to my linkedin profile, I get daily invitation to connect to people in the same industry without me doing any work, I just get invite daily and once a week I go in and screen each invite to make sure it’s not spam and accept it. How do I know if it’s spam? pretty simple really, 99% are legit, 1% of linkedin people are spamming because there isn’t much benefit because linkedin is not like social media facebook and twitter for everyone. Linkedin is a little more toward people that have real experience and the company they connected to is legit and verified by their peers. Sometime you will come across to some pretty face girl or sexy hot looking person, most of the time this indicate spam, or the profile written poorly too good to be true, it’s a spam. Newly created profile sometime or most of the time point to spam as well.