Fintech is a good keyword. But Fintech mostly using apps, and not much jobs in this category. FinanceJobs is a very great keyword.
IT, Cyber Security are very broad. In Fintech only staff, manager, IT, customer service, field collection, desk collection, legal I think. To compare, you can test by going to jobs portal and input the keyword in search bar. Surely IT, finance and Cyber Security will show thousands of jobs, and fintech will be shown only a view hundred jobs.
Fintech is a billion $ business, like Paypal, Skrill are categorized as Fintech
So for end user, it can be worth xxx to low xxxx $ for .net extension.