If I invest 1 BTC in TEK and get at least 30% per month, then I get 23 BTC after one year? Or may be it is some mistake?
Wrong, 1BTC staked monthly at 40% will yield 56.6BTC in exactly 1 year if you do not sell any of the stakes. You were not considering the compounding interest.
I made about 15 BTC in 3 months from Tek a while back. I bought around 1.2 BTC worth at around 1,000 sat, and staked for 3 months. Meanwhile, the price went up to over 5,000 sat and I couldn't resist taking my profit. True story.
Tek literally saved my trading career after I took huge losses from Litecoin and Bitcoin in early 2014. Tek has been around for a while and we should see a big rise in price soon. The dev has plans for it and is very active. With prices as cheap as they've ever been, NOW is the time to stock up and stake up!
Still overly simplistic, as this does NOT take into account trading prices. I've done alright with TEK, but at current prices, were I not altogether in stake profits now, I'd have lost money on the market downturn. I very distinctly remember 10K sats for a brief, shining moment. Sold off a lot back then, and bailed my ass out of a bad situation. But selling that same amount today wouldn't even get me 1BTC.