The market will resolve as “Yes” if there is a general consensus among experts that sentience has been created in a non-biological substrate by the end of 2030.
I will interpret "consensus" as roughly 90%+ agreement among experts. "Experts" for these purposes will likely include human philosophers, neuroscientists, and anyone else that is among the most knowledgeable in the world about the subject at the time. I will define "sentience" as the ability to perceive and feel things.
I may bet in this market.
Could we build an artificial sentience right now if we wanted? Probably: according to most theories of consciousness it isn't very hard, just build something with a global workspace, or that has perceptions that feed into beliefs or that has high integrated information, or that forms beliefs about its own perceptual states, all of which we can probably do now, unless you think "real belief" requires human-level general intelligence anyway. Will you actually get over 90% of experts on consciousness to agree that a particular system is sentient by 2030, almost surely not. (Lots of experts don't really trust any current theory, or have a replacement in mind.)