The Eyesir 4k (previewed here) is a fully spherical 360 camera with 4k video and is claimed to have 4k 360 livestreaming capability. Here are recently posted samples and information about pricing.
The Eyesir 4k has two lenses (f/2.2 aperture) paired with 13mp CMOS sensors. According to its manufacturer Perfant VR, the Eyesir 4k can take photos at 18mp (6000 x 3000) and take videos at 4k (4096 x 2048 @ 30fps). Unlike many other high-resolution 360 cameras, the Eyesir can stitch in realtime and can livestream in 360, supposedly at 4k resolution.
Here are more sample photos (note that some of the photos are from the Eyesir Mini, a lower-resolution camera).
Here is a sample 360 video: