I don't think there is any shortcut to significantly scale up your project. As you stated, social media is the obvious solution. It indeed takes a long time and even if you run ads it still takes time since there is a prerequisite you need to do, takes this, for example, if you doing ads, considering your lack quality of the channel, anyone wouldn't give a shit. Other than that, here a few suggestions:
Establish your trading setup ideas
I saw your TG, and you just woke up and only made a few calls after a long period of inactivity. Also, you need to somehow make every call counts, what I mean is, people could easily see whether your calls are on point or not.
Activate your social media and blog
Instead of reaching out to them, why didn't let them reach you by themselves. Building a strong social media presence would attract your site to the next level. Make content about trading on any platform would benefit you the most.
The last thing is maximize
Tradingview. You can make a call there, and if you have built a strong enough reputation, people would easily come to your group.