AGN fraction at z ≥ 8.5. The blue and red histograms present the number of AGNs and the sources that are spectroscopically confirmed in our studies at each M _UV bin. The histogram with a red outline represents the two possible AGN sources of ID10646 and ID3686 that fall in the brightest M _UV bin. The red circles indicate the AGN fraction for the spec-z-confirmed UNCOVER sources at z ≥ 8.5, where we show the brightest M _UV bin in the case that both AGN candidates are truly AGNs. The error bars represent the confidence intervals for the binomial proportion, derived using the Jeffreys interval at 1σ. The red hatched area shows the 1σ range for the AGN fraction over the entire M _UV range (=2/10). This may be a lower limit, as more sources, including ID10646 and ID3686, might be confirmed to be AGNs in future observations. The black shaded area denotes the recent reports of ≃5%−10% BL AGN fractions from the BL AGN identifications in recent NIRSpec studies at z ≃ 4–7 (Y. Harikane et al. 2024; R. Maiolino et al. 2024a).