At Photokina 2016 in an interview with Sigma’s CEO, he said Sigma currently is working on full frame E-mount lenses for Sony mirrorless cameras. Today, a source told us that first Sigma FE lens will coming sometime in 2017.
The source also said that we will see Sigma prime FE lens first, the price of Sigma FE lenses will be cheaper than native Sony FE lenses.
Currently, Rokinon/Samyang and Tamron have already released their FE lenses for Sony, seems Sigma will be the next company offers Sony FE lenses.