depends what kind of security researcher. AppSec is p hot rn. Mobile sec is p hot. Browser security research can still advance quite a ways. ExploitDev is alway

depends what kind of security researcher. AppSec is p hot rn. Mobile sec is p hot. Browser security research can still advance quite a ways. ExploitDev is always popular. Just depends what niche you want to go into. Once you know your niche, just start publishing research (vulns, analysis, something interesting FFS) and sharing it online. If the research is legit, it's not hard to get noticed.