Personally I prefer to speculate with proven extensions...
I think that with the stock market, crypto trading, and domain investing there is a spectrum with "investing" on the one side and "gambling" on the other...
I myself gamble as little as possible... and that means paying attention to past history and historical and current trends.
You'll see in the below graph that the
.life TLD is not very popular in comparison to the other extensions which I choose to pay more attention to:
If I WAS to speculate on the New gTLDs... then I'd do two things...
ONE
I'd choose combinations that made a LOT of sense... like for example
Home.Loans sold recently for $500,000 because it makes a lot of sense. I personally have one or two, but nothing that good at all... and no one is knocking on my door, so I imagine sales are a combination of luck, and perhaps doing really good marketing and outreach.
TWO
To lower risk I might only invest in the New gTLDs that have proven themselves: